PARIS —Police poured into Paris’ Gare du Nord station late Monday, evacuating passengers from platforms and sealing off the area in a new security scare to hit the French capital.

Paris police spokeswoman Johanna Primevert said the operation was aimed at “removing doubt” but would not say what prompted it or whether there had been any injuries or arrests. A station employee said the operation focused on a train from Valenciennes in northern France.

The busy station is the terminus of a large suburban and national rail network as well as Eurostar trains from London.

France is under a state of emergency imposed after a series of Islamic extremist attacks.