Brussels metro
A Belgian serviceman stands guard at the Maalbeek metro station on its re-opening day in BrusselsJohn Thys/ AFP

Police in Belgium have arrested four people in Antwerp, suspected of being recruiters for Islamic State (Isis). The four are thought to have been actively recruiting jihadi fighters to join the conflicts in Syria and Libya, while traces of a plot to launch attacks in Belgium were also uncovered, say authorities. A total of 32 victims were killed in the twin attacks in Brussels on 22 March, as well as three terrorists.

Belgium's federal prosecutor's office said, in a statement, that one of the four suspects remains in custody today (25 May). Three others have been released, two of them with strict conditions and another with an electronic tag. Eric Van der Sypt, from the prosecutor's office, told AP: "The four were more involved in the part of recruiting. And we found traces of plans for an attack in Belgium."

Searches have been conducted in Ternat, Antwerp and Borgerhout, but no weapons or explosive devices have been discovered, according to Bloomberg. The suspects are not thought to have been directly linked to the 22 March attacks and have been charged with participating in the activities of a terrorist group — namely Isis (Daesh). More young Belgians have gone to join IS in the Middle East than from any other European country.

The suicide bombings that detonated at the city's airport and Metro network on 22 March also left over 200 injured, and led to claims that some of the city's neighbourhoods were hotbeds of Islamic radicalism - claims which have been denied by many of the inhabitants of suburbs like Molenbeek. However, Abdelhamid Abaaoud - the ringleader of the Paris attacks in November 2015 - also came from Molenbeek, as did Salah Abdeslam, who is now appearing in court in France in connection with the terror attacks in Paris.