Police and France's railway operator say authorities briefly evacuated a train station in a bustling area near Paris' historic Opera house following a bomb alert.

Police say bomb squads and lab technicians turned up no explosives in a search at the Saint-Lazare station after an anonymous caller phoned in the bomb threat to police.

French authorities say France is facing an elevated terror threat. They suspect Al Qaeda's North African affiliate of plotting a bomb attack on a crowded target.

A bomb alert led police to evacuate the Eiffel Tower on Sept. 14, though no explosives were found.

The French Senate voted earlier this month to ban burqa-style Islamic veils in France, a subject that has prompted warnings by Al Qaeda's north Africa wing.

The Associated Press contributed to this report