Three detained after police worker stabbed to death near Paris
The murder at a police station in Rambouillet, a commuter town about 60 kilometres (40 miles) from Paris, revived the trauma of a spate of deadly attacks last year.
The victim was a 49-year-old woman named as Stephanie, a police administrative assistant and mother-of-two, who was stabbed twice in the throat at the entrance of the station. Her attacker was shot dead.
President Emmanuel Macron, who was out of the country on a visit to Chad in northern Africa, tweeted that France would never give in to "terrorism".
The latest bloodshed and violence targeting police is likely to focus attention further on the danger of Islamic extremism in France and wider concerns about security one year ahead of presidential elections.
France’s national anti-terrorism prosecutors have opened a terror investigation, while a source close to the inquiry told AFP the knifeman shouted "Allahu Akbar" (God is Greatest) during the attack.
Chief anti-terror prosecutor Jean-Francois Ricard, who spoke outside the station along with Prime Minister Jean Castex, confirmed "comments made by the assailant" indicated a terror motive.
The attacker, identified only as Jamel G., was fatally wounded when an officer opened fire on him.
He arrived in France illegally in 2009 but had since obtained residency papers, a police source said, adding that he was unknown to security services. He had just moved to Rambouillet.
Far-right leader Marine Le Pen immediately questioned why the attacker had been able to settle in the country and she hit back at recent criticism about police brutality in France.
"We need to get back to reason: supporting our police, expelling illegal immigrants and eradicating Islamism," she wrote on Twitter.
Polls currently show her running Macron close in next year’s election, though experts warn that surveys conducted so far from voting day and during a pandemic should be interpreted with caution.
About 30 police officers wearing balaclavas raided the suspect’s home in Rambouillet on Friday evening as they sought information about his motive and contacts, AFP reporters at the scene said.
At the same time police in the Paris region searched the home of the person who had sheltered Jamel G when he first arrived in France, sources close to the inquiry said.
Three people were arrested in total, a judicial source told AFP on condition of anonymity.
Interior Minister Gerald Darmanin, who also visited officers in Rambouillet, said security would be stepped up at stations nationwide.
France has been repeatedly targeted by attackers since 2015, with a series of incidents in the last year keeping terrorism and security as a leading concern.