In compiling data for the report, ICCT conducted a survey among 23 EU member states and found that the number of foreign fighters from those countries totals 3,710. However, open source information suggests that the number of radicals from all the countries comprising the union lies between 3,922 and 4,294, it was concluded in the report.
"Many consider returning FF [foreign fighters] as a potential security threat; this research indicates that an average of 30% of FF have returned to their countries of departure," the report reads.
Belgium, as the highest per-capita contributor of foreign fighters to jihadist groups, has recently seen an escalation of terror-related incidents. Two suicide blasts ripped through the departures hall of Brussels Airport on March 22. A further explosion occurred at the Maelbeek station near the headquarters of the EU institutions. A total of 35 people died in the attacks, while more than 300 were injured.