Police in Belgium have made 12 arrests during a huge anti-terror operation, about three months after the deadly bomb attacks on Brussels.

Those detained are suspected of plotting a terrorist attack, prosecutors say. They were among 40 taken in for questioning, BBC reports.

Searches were conducted in 16 municipalities, mainly around Brussels, with checks on 152 lock-up garages.

No arms or explosives were found during the searches, while the federal prosecutor said the operation had been launched after investigations which “necessitated an immediate intervention”.

It is said that Belgian police have recently received a warning that a group of ISIS militants has left Syria heading towards Europe and plans new attacks in Belgium and France.