According to De Morgen newspaper, reports come from vigilant citizens, social workers and prison guards.
Within the last several years, Belgium was shaken by a number of terror attacks. On 29 May, a man attacked two police agents in the Belgian city of Liege with a knife, took hold of their arms and shot them and then one passer-by dead on Tuesday, in what local prosecutors are investigating as a potential terrorist attack. The perpetrator was killed by the police. According to media reports, the man, who was well-known to the police for theft, vandalism and small-time drug trafficking, was radicalized in the prison of Lantin.
The March 2016 bombings in Brussels metro and airport left more than 30 people dead and over 300 injured, leading to the introduction of the highest forth terror threat level, which was subsequently lowered.
As of 2017, some 19,000 people were on the police list of individuals suspected of ties to terrorists, which is 10 times more than in 2010, the RTL broadcaster reported citing the Federal Public Service Interior.