Police stormed into a Paris train station late Monday, evacuating passengers and cordoning off the area over an unspecified security threat. The station was shut down for about three hours before police allowed operations to resume. Witnesses said police officers poured into the Gare du Nord station and quickly began rushing passengers out of the area, sealing the station off completely. Photos from the scene showed heavily armed police in position with their weapons at several entrances to the station. A police spokeswoman was quoted by the Associated Press saying the operation was aimed at “removing doubt,” though she gave no further details on what prompted the evacuation. The incident comes as France is still under a state of emergency after a spate of deadly terrorist attacks in recent months. A station employee who spoke on the condition of anonymity said police were focused on a train from the northern city of Valenciennes. It was not immediately clear how many officers were deployed for the operation, but a witness said police buses and unmarked cars were “driving quite dramatically up the road” after passengers were evacuated.