The police opened fire during the operation at the Gare du Nord and the perpetrator was injured, a police source told the AFP news agency.

The victims must be relatively slightly injured.

The motive for the crime, which occurred at 6:45 a.m., is initially unknown.

"One person injured several people during the morning at Gare du Nord.

He was quickly neutralized.

Thanks to the police for their effective and courageous response," tweeted Interior Minister Gérald Darmanin, who said he plans to visit the crime scene.

The area has been cordoned off and the act has led to major disruptions in train traffic during the morning rush hour, reports French BFMTV.

Gare du Nord is one of the world's largest railway stations and has the most traffic users in Europe.

The station is a hub for trains to London and Northern Europe.