Paris's busy Gare du Nord station was evacuated for more than two hours overnight Monday while police launched a major search operation on a train for three wanted people.
The international transport hub was evacuated shortly before midnight Monday to allow members of the Research and Intervention Brigade (BRI) police unit to search the train which had come from the northern city of Valenciennes, according to a source close to the enquiry.
Police ended the operation at 01:50 am Tuesday (2350 GMT Monday) without success.
"Checking complete, gradual return to normal," police tweeted.
The team were deployed after the alarm was raised by ticket office staff, sources said.
The operation comes two weeks after armed police arrested a man carrying a knife at the station, sparking panic in France, which has suffered a string of deadly attacks in recent years.