A man has died after ramming a car carrying weapons and explosives into a police van as it drove down Paris' Champs Elysees, prompting a fiery blast, officials say.
Interior Minister Gerard Collomb said the man was killed after an attempted attack on a police convoy.
Two police officials told The Associated Press that a handgun was found on the driver, who they said was badly burned after the vehicle exploded.
They identified the man as a 31-year-old from the Paris suburb of Argenteuil who had an "S'' file, meaning he was flagged for links to extremism.
Mr Collomb said the man's car was carrying weapons and explosives that could have caused a blast.
"This once again shows that the threat level in France is extremely high," Mr Collomb told journalists not far from the scene.
Police cordoned off a large part of the Champs-Elysees after the incident, warning people to avoid the area.
A man could be seen lying on his stomach on the ground immediately after the incident, wearing a white shirt and dark shorts.
Hours later, access to the avenue remained blocked, while bomb squads combed the area.
The Paris prosecutor's counterterrorism unit said an investigation had been opened into the incident, which happened only a short walk from the Elysee presidential palace and the US embassy.
A police source also told Reuters that the man was known to security services.
No police officers or passers-by were hurt, the Paris police department said.
President Emmanuel Macron said last month his Government would ask parliament to extend wider search and arrest powers granted under a state of emergency called after Islamist gunmen and suicide bombers killed 130 people in and around Paris in November 2015.
Some magistrates and human rights groups have protested in recent weeks against the proposal that would enshrine in ordinary law measures currently in place under the state of emergency.