A security operation is under way in Paris around the Champs Elysees area, after a car crashed into a police van before bursting into flames, officials say.
The driver is “on the ground… unconscious,” French news agency AFP reports, quoting a police source.
It was not immediately clear if the incident was accidental or deliberate.
France is currently in a state of emergency after being hit by a wave of deadly terror attacks in recent years.
A policeman was shot dead and two others were wounded in an attack on the Champs Elysees in April, just days before the presidential election.
The national police Twitter account said (in French) that there was an “ongoing police operation”, warning people to respect the security cordon.