A terrorism investigation has been launched after a man fatally stabbed a police administrative worker as she walked into a police station in a Paris commuter town on Friday.
The attacker stabbed the woman in the throat, two security sources said.
President Emmanuel Macron said on Friday that France had again been the victim of a terrorist attack.
“We will stop at nothing in our resolute fight against Islamist terrorism,” Mr Macron tweeted.
The attacker was shot dead by police officers.
France’s anti-terror prosecutor said he was leading the investigation into the stabbing incident because the assailant had previously scouted out the site and because of what he said during the attack.
A judicial source close to the investigation said the attacker had shouted “Allahu Akbar”, or “God is Greatest”.
The attacker was a Tunisian national residing in France on legitimate papers, the security officials said. BFM TV reported that he had lived in France illegally before obtaining a residency card, which was due to expire later this year.
He was not previously known to France’s intelligence agencies, a third security source added.
Prime minister Jean Castex said France had lost an “everyday heroine” to an act of infinite cowardice.
The police station was located on a leafy residential street in Rambouillet, a middle-class town about 50km southwest of Paris.
The victim had two daughters, said Michel Camboulives, whose partner was a colleague and close friend of the victim. He said his partner described her as an adorable woman.
“I don’t know how such things happen here,” Mr Camboulives said. “I mean, we’re in France.
“My partner’s just in pieces. This was her best friend. She couldn’t speak on the phone.”
France has seen several attacks by Islamist militants or Islamist-inspired individuals in recent years that have killed about 250 people.
Friday’s attack came six months after a Chechen teenager beheaded a school teacher in Conflans, another Paris satellite town.
Mr Castex, interior minister Gérald Darmanin and other top officials visited the scene of the attack to show their support for police. – Reuters/AP