BRUSSELS (AP) — Belgian authorities have detained 12 people for interrogation following raids linked to last year’s Brussels attacks.

Police raided 14 places in and around Brussels on Tuesday and an investigating judge will decide later whether any of the detainees will be charged.

The federal prosecutor’s office refused to elaborate beyond a terse statement.

On March 22 last year, 32 people were killed in twin attacks on the Brussels airport and the subway system. Belgium is still in a heightened state of security.