Belgian authorities have launched a series of raids in Brussels linked to a recruiting network for the Islamic State group and detained 10 people.
The federal prosecutor's office said in a statement Tuesday that nine raids were carried out in four suburbs, including the Molenbeek neighborhood where many extremists have stayed.
Computer material and mobile telephones were seized during the raids and they are currently being examined.
The statement said the police action has helped "to establish that several people have probably gone to Syria to join Islamic State."
A judge is due to decide later on Tuesday whether those detained should be charged.
The raids are not linked to the deadly attacks in Paris last year.