French police have arrested more than a dozen people near Paris, and seized a handgun in a suspected terrorist hideout.
Anti-terror police would not comment beyond saying the arrests were not connected with last-week's police raid in Italy, where police detained a man wanted by Spanish authorities in connection with the Madrid bombings in March.
Under French anti-terrorism law, the police can hold the suspects in custody for four days without bringing charges.
The suspects, police say, included French nationals of Moroccan origin and illegal immigrants from Morocco. They were arrested in an early morning police raid at their homes in the Paris suburbs.
Police said a search of the suspects' homes netted, among other things, a handgun and supplies to manufacture fake identity cards. Spokeswoman for the prosecutor's office, Maryvonne Caillibotte, said the object found in the suspects' home may well have been used in connection with terrorist activities.
Last week, in a coordinated sweep, police in Belgium and Italy arrested 17 suspected Islamist militants, including a suspected organizer of the Madrid train bombings that killed 191 people.