Police shot and seriously wounded a man who injured an officer with a knife near the famed Champs-Elysees avenue in Olympic host city Paris on Thursday, police sources told AFP.
Police said a terrorist motive was not suspected, but the violence added to tensions as Paris prepares to host the Olympic Games from July 26.
The assailant suffered life-threatening injuries when he was shot by another officer, according to the police source.
Paris police prefect Laurent Nunez said the man had been reported by staff at a Louis Vuitton boutique, who requested police to intervene.
"At the sight of the police, the man fled with a knife in his hand, then turned around and wounded a policeman," said another police source.
Nunez told reporters the officer was seriously injured to the neck but his life was not in danger.
He said there was no known "terrorist motive at this stage, and no link to the Olympic Games".
A source in the prefecture said the attacker was a Senegalese national and was previously known to police.
Near the scene of the attack, a bomb disposal truck and several police trucks were parked, an AFP journalist saw. Crime tape encircled the entire area.
"A police officer was the victim of an attack in the eighth arrondissement of Paris while responding to a call from officers securing a store," Interior Minister Gerald Darmanin said on X.
"The perpetrator was immediately neutralised by police officers providing security," he added.
France is on high alert ahead of the Games, having been the victim of numerous terror attacks in recent years.
On Wednesday evening, a motorist ploughed a car into a cafe terrace in northern Paris, killing one person and seriously injuring several others.
Prosecutors said the driver was committed for psychiatric treatment.
On Monday, a soldier was stabbed in the back by a 40-year-old man at a major train station in northern Paris.
Officials said the soldier's life was not in danger.
Thousands of security personnel locked down a six-kilometre (four-mile) stretch of central Paris on Thursday ahead of the Olympics opening ceremony.
Officials say 35,000 police officers and 18,000 soldiers will provide security for the Games.
More than 300,000 spectators are expected to watch the opening ceremony along the banks of the Seine.
National anti-terrorism prosecutor Olivier Christen on Tuesday said the Games "are not the subject of specific targeting by international terrorist organisations".
