A man stabbed a policewoman in the town of La Chapelle-Sur-Erdre in western France, leaving her critically injured before he was arrested in a shootout, police and media said.
The exact motive behind the stabbing is unknown.
The police said the man stole the officer’s weapon and fled in a car before a crash forced him to continue on foot.
French news channel BFMTV reported that the attacker was caught in a manhunt that involved two police helicopters and more than 200 officers.
The victim was in a critical state, the media reported.
Schools nearby were under police protection.
The incident comes a month after a female police officer was knifed to death near Paris by a Tunisian national who had watched religious videos glorifying acts of jihad just before waging his attack.
Interior Minister Gerald Darmanin said he was travelling to the scene of Friday's attack.
Tackling domestic security is likely to be at the centre of the campaign ahead of next year's presidential election.
Marine Le Pen, leader of the far right and the strongest challenger to Emmanuel Macron's expected re-election bid, paints the president as weak on security and says the police need more protection.
