Between 2020 and 2025, Belgium witnessed a troubling rise in incidents linked to radical Islamist ideology, raising deep concerns about national security and the integrity of democratic institutions. While Belgium has long been a multicultural society, the persistence of extremist networks, ranging from radical preachers to terror-linked individuals, has exposed the vulnerabilities of the state’s security apparatus. This report compiles 15 such incidents from the past five years, each revealing how pockets of radicalisation continue to operate beneath the surface, often undetected until an attack is attempted or a plot is exposed.

The pattern emerging from these events shows a gradual but steady escalation in both ideological aggression and operational boldness. These include attempted terror attacks, recruitment activities, extremist propaganda dissemination, and targeted threats against public institutions. Many cases also highlight how returning foreign fighters, previously convicted extremists, or radicalised individuals residing within migrant communities have continued to challenge Belgium’s counter-terrorism framework. The arrest of former Tunisian footballer Nizar Trabelsi on November 16, 2025, for planning a suicide attack on a NATO-linked air base, despite his prior criminal history, illustrates the recurring threat posed by radicalised individuals who continuously re-enter the extremist ecosystem.

Overall, the incidents documented in this report underline a broader and more systemic issue: the entrenchment of radical Islamist ideology within certain segments of society, capable of influencing vulnerable youth, destabilising neighbourhoods, and undermining public safety. By presenting these cases, this report seeks to highlight the urgent need for stringent counter-radicalisation policies, community vigilance, and stronger governmental oversight to prevent Belgium from becoming a safe space for extremists who aim to exploit democratic freedoms for violent ends.

1. Belgium pays €350,000 to a former Al-Qaeda terrorist after an illegal U.S. extradition

The case of Nizar Trabelsi resurfaced in 2025 as one of Belgium’s most alarming reminders of radical Islamist penetration within Europe. A former professional footballer who turned into a committed Al-Qaeda operative, Trabelsi had originally been arrested in September 2001 for planning a suicide attack on the NATO-linked Kleine-Brogel air base. His intent was to inflict a large-scale mass-casualty attack targeting American military personnel stationed in Belgium. Despite receiving a 10-year prison sentence, Trabelsi remained a symbol of how deeply embedded jihadist networks were across Western Europe even before the 9/11 attacks.

Belgium’s decision in 2025 to pay €350,000 in compensation to Trabelsi, following a court ruling that his 2013 extradition to the United States had violated Belgian sovereignty, sparked major controversy. The payout was viewed by many as a deeply unsettling consequence of legal technicalities overshadowing national security priorities. Critics argued that while Belgium has strong human-rights frameworks, compensating a convicted Al-Qaeda terrorist risked sending a dangerous message: that extremist operatives could exploit legal loopholes for financial or political gain. The case also raised broader concerns about Europe’s inconsistent approach to handling high-risk jihadists linked to international terror networks.

Trabelsi’s renewed prominence in 2025 underscored Belgium’s long-term struggle with radical Islamist elements capable of organizing attacks against state and military institutions. His background, radicalization path, and persistent attempts to avoid accountability demonstrated how extremist ideology, once entrenched, remains a sustained threat.

2. Three arrested in Belgium over alleged jihadist plot targeting PM

Belgian authorities thwarted a major assassination attempt in November 2025 when intelligence agencies intercepted a jihadist plot targeting the country’s Prime Minister. The suspects had been developing a sophisticated attack plan centered on using a drone equipped with an improvised explosive device packed with steel balls, clearly designed to maximise lethality. Anti-terrorism units acted swiftly, conducting coordinated raids that resulted in the arrest of all three suspects before they could mobilize their weaponised drone system.

Investigations revealed that the group had used a 3D printer to manufacture critical components for the explosive device, demonstrating the increasing role of modern technology in extremist operations. Belgian security services further uncovered detailed notes, digital communications, and encrypted files indicating a well-orchestrated jihadist conspiracy with potential external guidance. The plot illustrated how extremist cells were becoming more adaptive, innovative, and capable of using commercially available technology to bypass traditional counter-terror surveillance.

The attempted attack marked one of the most serious direct threats to Belgian political leadership in recent years, raising the national terror alert level and prompting extensive security reviews. Authorities emphasized that the plot reflected a broader trend of radical Islamist groups targeting symbols of state power. The arrests demonstrated Belgium’s ongoing exposure to violent extremism and reinforced the urgent need for improved technological intelligence, drone-defense mechanisms, and early-warning systems to prevent similar high-risk plots in the future.

3. Belgian court convicts jihadist for Yazidi genocide

In a landmark verdict, a Brussels court convicted ISIS fighter Sammy Djedou for genocide against the Yazidi community, marking Belgium’s first-ever prosecution for mass atrocities committed during the Islamic State’s reign of terror. Djedou, once reported killed in a 2016 airstrike, was instead found to be alive and was tried in absentia. The court concluded that he played a direct role in ISIS operations aimed at exterminating Yazidis, including participating in mass executions, forced conversions, and targeted violence that formed part of the Islamic State’s genocidal campaign.

The prosecution detailed Djedou’s involvement in rape, sexual enslavement, and the brutal subjugation of Yazidi women and girls, providing harrowing evidence of ISIS’s systematic use of gender-based terrorism. Survivors’ testimonies, intelligence reports, and forensic material collectively painted a chilling picture of his crimes. Belgium’s decision to pursue the case, even without the physical presence of the accused, was seen as a rare example of a European nation willing to hold extremist fighters accountable for atrocities committed abroad.

This conviction represented a major judicial breakthrough at a time when many European countries have struggled to prosecute returning foreign fighters due to evidentiary challenges. Belgium’s stance signalled its recognition of the global threat posed by radical Islamist ideology and the need to ensure justice for victims beyond its borders. The verdict also highlighted that while ISIS lost territorial control, its ideological remnants remained active and continued to pose legal, moral, and security dilemmas for European governments.

4. Belgium introduces a bill to ban extremist groups, including the Muslim brotherhood

In July 2025, Belgium took a decisive step to counter the growing influence of radical Islamist networks by introducing a landmark bill aimed at banning extremist organisations operating within the country. The proposal, unveiled by the Prime Minister, sought to give the government legal authority to disband any group deemed a threat to democratic institutions and national security. The move followed years of intelligence warnings that ideological groups, particularly those aligned with the Muslim Brotherhood, were escalating recruitment, foreign funding activities, and infiltration attempts across European civic structures.

The government highlighted that groups like Samidoun and Brotherhood-connected organisations had repeatedly propagated extremist ideology through community centres, student groups, and political activism disguised as humanitarian causes. Internal security services reported that such entities were not merely ideological but acted as logistical nodes, enabling transnational extremist ecosystems to take root. The bill represented Belgium’s acknowledgment that radicalisation does not occur only through violent militancy but also through structured ideological grooming that undermines democratic norms from within.

The legislation triggered intense debates, with critics claiming potential restrictions on civil liberties, while supporters argued that Islamist extremist networks often exploit democratic freedoms as shields for subversion. Belgian officials maintained that the proposal was necessary to stem the ideological spread that has historically preceded acts of violence across Europe. The bill marked a significant shift in Belgium’s counter-radicalisation strategy, moving from mere surveillance and criminal prosecution toward dismantling foundational extremist infrastructure before it evolves into violent extremism.

5. Three suspected IS members charged in Belgium over terrorism plot

Belgium’s federal security services intercepted a high-risk ISIS-K terror cell in July 2024, charging three individuals with plotting a large-scale terrorist attack. The arrests followed extensive nationwide raids that targeted extremist hideouts and communication hubs linked to the Islamic State’s Khorasan affiliate, one of the most aggressive ISIS factions still operational globally. Authorities confirmed that the suspects had been under long-term digital and physical surveillance due to their connections with jihadist networks active in Central Asia and Europe.

Investigators discovered that the suspects were coordinating potential attacks to coincide with heightened global security-sensitive periods, particularly in the lead-up to the Paris Olympic Games. Intelligence agencies found encrypted files, radical propaganda, and communication logs showing the suspects’ attempts to acquire weapons and chemical precursors. The sophistication of their operational planning signaled a concerning shift in ISIS-K strategy, from regional insurgency to transcontinental terror ambitions aimed at European civilian and symbolic targets.

This case reinforced Belgium’s position as a recurring focal point for jihadist plots attempting to exploit its geopolitical location, multicultural society, and dense urban environment. Authorities stressed that despite territorial losses in the Middle East and South Asia, ISIS networks remained capable of activating sleeper cells in Europe. The arrests highlighted the persistent necessity for cross-border intelligence cooperation among EU states and demonstrated Belgium’s proactive commitment to preventing extremist plots before they transition into active attacks.

6. Four suspects plotted attack on brussels botanique concert hall

On March 4, 2024, Belgian police disrupted a chilling terror plot aimed at the iconic Botanique concert hall in Brussels. The investigation revealed that a group of four individuals, three of them minors, had been radicalised online and were actively coordinating an attack inspired by ISIS propaganda. Their encrypted conversations referenced past Islamic State operations and glorified mass-casualty events, indicating an advanced ideological commitment despite their young age. Authorities launched an immediate anti-terror sweep, detaining all four suspects before the plot could be executed.

The group had been searching for weapons on the dark web, demonstrating the growing trend of technologically facilitated radicalisation among European youth. Their attempt to obtain firearms and explosive materials showcased the dangerous convergence of online extremism, anonymous marketplaces, and minimalist attack methodologies. The adult suspect, acting as the operational anchor, was formally charged with participating in a terrorist organisation and preparing a terrorist act, while the minors were placed under juvenile anti-terror proceedings.

The plot underscored Belgium’s escalating challenge of countering youth radicalisation driven by extremist digital ecosystems. Security officials warned that online platforms had become recruitment incubators where vulnerable teenagers could be manipulated into violent jihadism within weeks. The Botanique case served as a stark reminder that even entertainment venues, symbols of culture and public freedom, remain high-value targets for ISIS-inspired cells. Belgium’s counter-terror agencies urged families, schools, and community institutions to recognise early signs of online radicalisation to prevent similar cases.

7. Belgium records 41% jump in terrorist and extremist threats in 2023

Belgium’s Coordination Unit for Threat Analysis (CUTA) released a stark assessment in March 2024, reporting a 41% surge in terrorist and extremist threats in the preceding year. With 332 verified threat reports compared to 236 in 2022, the data reflected an escalating climate of hostility driven largely by radical Islamist elements. Many of these threats were communicated through anonymous emails, phone calls, or online platforms, indicating that extremist actors were increasingly adopting low-cost psychological intimidation tactics to destabilise Belgian society.

CUTA’s analysis further highlighted that over 40% of all threats had direct links to Islamist extremism, reaffirming that radical jihadist ideology continued to exert influence despite notable counter-terrorism operations in recent years. Officials warned that Belgium’s complex demographic landscape, combined with the presence of individuals previously affiliated with foreign terrorist organisations, heightened the nation’s vulnerability to ideological infiltration. The intelligence community also expressed concern over “hybrid threats,” where online propaganda encouraged lone-actor attacks that are harder to predict and prevent.

The dramatic increase in threats prompted the Belgian government to reassess its national security framework, with calls for enhanced monitoring of radicalisation hotspots, educational outreach, and community-level deradicalisation programs. CUTA emphasised that Belgium remained a preferred target for extremist messaging due to its symbolic political institutions and multicultural population. The 2023 data ultimately served as a warning that the environment fueling Islamist extremism had not diminished, and that Belgium must adapt rapidly to counter these evolving threats.

8. Tunisian ISIS-inspired gunman kills two Swedish soccer fans in brussels

On October 16, 2023, Belgium suffered one of its most shocking lone-wolf Islamist attacks in recent years when Tunisian national Abdesalem Lassoued opened fire on Swedish football fans in Brussels. Armed with an automatic rifle, Lassoued targeted the victims deliberately, killing two Swedish men and triggering widespread panic in the capital. His attack was filmed and circulated online, with the shooter declaring allegiance to ISIS, demonstrating that the ideological reach of the Islamic State remained potent despite its territorial defeat.

The attack exposed glaring systemic failures, including the fact that Lassoued had been living illegally in Belgium and was known to law enforcement for radical sympathies. Authorities quickly elevated the nation’s terror alert level to its highest tier as they initiated a massive manhunt. Lassoued was later tracked down in a café in Schaerbeek, where he was shot by police and died shortly afterward in hospital. His ability to remain undetected despite asylum-related red flags raised new questions about Belgium’s immigration controls and security vetting.

This incident deeply strained Belgium’s international relations, particularly with Sweden, whose citizens were the targeted victims. It also reignited the domestic debate over Europe’s ongoing struggle to manage undocumented migrants with known extremist leanings.

9. Eight men found guilty over brussels 2016 terror attacks

In July 2023, Belgium concluded one of the largest terrorism trials in its history, convicting eight men for their involvement in the 2016 Brussels bombings, a coordinated ISIS attack that struck Zaventem Airport and Maelbeek metro station. The trial offered a detailed reconstruction of the terror cell’s operations, revealing that the perpetrators were part of a broader ISIS network linked to the Paris 2015 attacks. The verdict symbolized justice for the 32 victims who lost their lives and the more than 300 people who suffered life-altering injuries.

Key defendants included notorious terrorists Salah Abdeslam and Mohamed Abrini, whose extremist activities traced back to recruitment hubs in Belgium’s radicalised neighbourhoods. Evidence presented in court demonstrated that the cell had obtained explosives, orchestrated logistics, and coordinated movements across European borders with alarming ease. The trial exposed how European intelligence gaps, delayed communication, and fragmented oversight contributed to the attackers’ ability to strike with devastating precision.

The convictions served as a major milestone in Belgium’s counter-terrorism efforts, reaffirming its commitment to dismantling Islamist extremist networks operating within its territory.

10. Belgian police arrest seven people over Islamic state terror attack plot

On May 4, 2023, Belgian police conducted coordinated counter-terrorism raids across western Belgium, leading to the arrest of seven individuals linked to the Islamic State. The suspects were believed to be plotting a sophisticated terror attack against an institution within Belgium, with early intelligence indicating a potential high-casualty scenario. Authorities acted on months of surveillance data that showed increasing communication between the suspects and established ISIS channels abroad, reinforcing fears that Belgium continued to serve as an operational node for extremist networks.

Search operations were executed at nine separate locations, where investigators uncovered digital evidence, extremist material, and initial components of a possible explosive device. The suspects were formally placed under investigation for attempted assassination, participation in a terrorist group, and preparing a terrorist act, charges that underscored the severity of the threat. Belgian security officials indicated that the group had been exploring methods to conduct an attack that would generate both physical and psychological shockwaves across the nation.

11. Belgian police arrest eight Islamist extremists in counter-terrorism raid

Belgian police launched a major multi-city counter-terrorism operation on March 28, 2023, arresting eight individuals tied to radical Islamist movements. Raids were executed in Brussels, Antwerp, and Eupen after intelligence services detected coordinated efforts by the suspects to plan terror attacks. The individuals were identified as part of a loose but active extremist network that had been under observation due to their consumption and circulation of jihadist propaganda.

During the raids, authorities seized digital devices, encrypted communication tools, and materials linked to extremist indoctrination. Investigators reported that the suspects were exploring potential targets and attack strategies consistent with the Islamic State’s call for lone-wolf or small-cell attacks across Europe. While a final attack plan had not yet been executed, the suspects’ increasing radical behaviour, ideological commitment, and coordination raised significant alarms.

The operation was hailed as a preventive success, demonstrating Belgium’s capacity to intercept plots at the precursor stage. Security officials stressed that the incident reflected an evolving pattern: small extremist cells forming organically through online echo chambers, radical networks, and community-based recruiters.

12. Belgian police officer stabbed to death in terror attack at brussels train station

The deadly stabbing attack at Brussels North train station on November 11, 2022, marked one of Belgium’s most tragic reminders of the continuing threat posed by lone-actor Islamist extremists. Two police officers were assaulted by an individual armed with a knife who shouted Allahu Akbar during the attack, a clear indication of ideological motivation. One officer was fatally stabbed, while another sustained serious injuries, before the attacker was shot and neutralised by a responding patrol unit.

Subsequent investigations revealed that the perpetrator was a known extremist with a history of mental instability and radicalised beliefs. Alarmingly, the attacker had visited a police station earlier that same day expressing violent thoughts, yet was released due to procedural limitations, an oversight that sparked national outrage. The case exposed deep challenges in Belgium’s ability to handle individuals who present simultaneous psychiatric and extremist risk profiles.

The attack led to widespread calls for reforming Belgium’s threat-assessment protocols, particularly for individuals who signal imminent danger. Policymakers demanded stronger coordination between mental-health institutions, law-enforcement agencies, and counter-terrorism units to prevent similar tragedies. The murder of a police officer in such a brazen Islamist-motivated attack reinforced the urgent need for strengthened early-warning systems, enhanced officer safety measures, and more assertive interventions when radicalised individuals display violent intent.

13. Iranian diplomat convicted in France bomb plot in Belgium

The conviction of Iranian diplomat Assadollah Assadi in February 2021 marked one of the most unprecedented terror cases in European history. Assadi, an accredited diplomat stationed in Vienna, was found guilty by a Belgian court for orchestrating a plot to bomb a major political rally of Iranian dissidents near Paris in 2018. Belgian investigators revealed that Assadi personally transported explosive materials using diplomatic channels and delivered them to a Belgian-Iranian couple tasked with executing the attack. The case shattered long-standing assumptions that diplomatic immunity could not be weaponised for terrorism.

Evidence presented in court demonstrated that Assadi was not acting independently but belonged to an Iranian intelligence apparatus trained to target political opponents across Europe. Belgian prosecutors emphasized that the device he supplied was powerful enough to cause mass casualties among the 25,000 attendees present at the rally, including international dignitaries and lawmakers. His accomplices were also convicted, with Belgian security services stressing that the plot, if successful, would have resulted in one of the deadliest terror attacks in Western Europe in the 21st century.

The sentencing of Assadi to 20 years in prison sent a strong message to state-backed Islamic extremist networks that Europe would not tolerate the use of diplomatic cover to facilitate terrorism. The case heightened diplomatic tension between Iran and European nations, and it prompted policymakers to reassess the threat posed by state-sponsored Islamic extremism. Belgium’s ability to expose, intercept, and prosecute this cross-border plot was hailed as a milestone in European counter-terrorism efforts, underscoring the country’s central role in safeguarding continental security.

14. Belgium bans halal slaughter methods

On January 1, 2021, Belgium implemented a nationwide ban on traditional halal slaughter methods that do not involve pre-stunning animals, igniting intense backlash from Muslim organisations. The roots of the ban traced back to 2019, when regional governments in Flanders and Wallonia introduced restrictions based on animal-welfare standards. A Belgian court ruling in late 2020 affirmed that methods involving slaughter without stunning were incompatible with the country’s legal frameworks, leading to immediate enforcement of the policy in 2021.

Muslim groups argued that the ban represented a direct infringement on religious freedom and disproportionately targeted Islamic practices, particularly as kosher slaughter had already faced similar restrictions. For many Islamic councils, the decision was seen as part of a broader societal pattern in which Western European nations increasingly challenge religious customs associated with Muslim communities. Protests and legal appeals intensified, with critics warning that the ban risked fuelling alienation and enhancing the appeal of hardline religious narratives.

Belgian officials defended the measure as a necessary compromise between respecting religious traditions and upholding modern animal-welfare standards. They emphasized that the law was intended to promote humane slaughter practices rather than targeting specific religious groups. However, the controversy resurfaced debates over integration, secularism, and the influence of Islamist advocacy groups that often respond to such policies by amplifying radical rhetoric.

15. Two teenagers arrested in Belgium over suspected terror plot

Belgian authorities arrested two teenage boys on November 5, 2020, after uncovering an ISIS-inspired terror plot targeting police officers. The suspects, both minors, had recorded a video pledging allegiance to the Islamic State and expressing their intention to carry out a stabbing attack. Raids conducted in Eupen and La Calamine led to the seizure of extremist propaganda and digital communications showing deliberate preparation for an imminent assault. The arrests highlighted growing concerns about early-age Islamic radicalisation within certain communities.

Investigators revealed that the teenagers had been consuming large volumes of ISIS material online and were deeply influenced by digital recruitment ecosystems operating through encrypted channels. Their plans mirrored ISIS’s repeated calls for lone-wolf attacks against law-enforcement officers in Europe, strategies designed to exploit vulnerable youth and destabilise domestic security frameworks. Authorities noted that the minors exhibited a disturbing level of ideological conviction despite their young age, pointing to the effectiveness of online radical grooming.

The case triggered renewed national debate on how Belgium should respond to extremist radicalisation among minors. Officials stressed the need for more robust monitoring of online spaces, expanded psychological intervention programs, and closer collaboration between schools, parents, and counter-extremism agencies. The incident also served as a stark warning that ISIS’s influence remained potent among youth populations, even years after the group’s territorial collapse. Belgium reaffirmed its commitment to early-stage prevention as a core pillar of its anti-terrorism strategy.