At least six people were lightly wounded on Wednesday by a man wielding a knife at the busy Gare du Nord station in Paris, French police sources said.

The attacker was shot several times by police and taken to hospital with serious injuries, police said. The man's motivations were not immediately clear, the force added.

One police source said the police officer who shot the attacker was off-duty.

The station is one of the busiest in Europe and a major link between Paris, London and the north of Europe.

Police secured the area following the attack, which happened around 6:45 a.m. local time (5:45 a.m. GMT).

Radio franceinfo, quoting rail operator SNCF, said trains were operating normally.