French prosecutors opened a terror probe on Friday after a woman working for the police was stabbed to death at a police station southwest of Paris by a Tunisian man who was then shot dead by the security forces.

The attack at the station in Rambouillet, a well-heeled usually peaceful commuter town about 60 kilometres from Paris, revived the trauma of a spate of deadly attacks last year in France blamed on Islamist radicals.

France's national anti-terrorism prosecutors said they had opened a terror investigation, also involving the DGSI domestic intelligence service, into the murder of a person holding public authority.

The attack took place in the secure entrance area of the station at around 2:20 pm (1220 GMT), a police source added, asking not to be named.

The 49-year-old woman, an administrative assistant who was returning from a lunch break, was stabbed in the throat twice and died of her wounds shortly afterwards, the source said.

The attacker was fatally wounded when an officer opened fire on him. The murdered woman was the mother of two children aged 13 and 18.

Prime Minister Jean Castex, who arrived at the scene, denounced on Twitter a "barbaric act of boundless cruelty" against "a hero of daily life."

"I want to tell the police I share their emotion and their outrage," he added.

The assailant, aged 36, 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.

French Prime Minister Jean Castex (C) and French Interior Minister Gerald Darmanin (L) talk to the press. Photo: AFP

Spate of attacks

Several attacks over the last year have reignited concerns about the spread of radical Islam inside France as well as immigration.

In September, a Pakistani man wounded two people with a meat cleaver outside the former offices of satirical magazine Charlie Hebdo which had printed cartoons of the Prophet Mohammed.

On October 16, a young Chechen refugee beheaded teacher Samuel Paty who had shown some of the caricatures to his pupils.

And on October 29, three people were killed when a recently arrived Tunisian went on a stabbing spree in a church in the Mediterranean city of Nice.

In the most severe recent attack against French police, three officers and one police employee were stabbed to death in October 2019 by an IT specialist colleague who was himself then shot dead.

He was later found to have shown an interest in radical Islam. 

These attacks came after the massacres carried out by Islamist extremists from 2015 that began with the massacre of staff in the offices of Charlie Hebdo in January that year.

In France's deadliest peacetime atrocity, 130 people were killed and 350 were wounded when Islamist suicide bombers and gunmen attacked the Stade de France stadium, bars and restaurants in central Paris and the Bataclan concert hall in November 2015.

And in 2016 a man rammed a truck into a Bastille Day crowd in Nice in 2016, killing 86 people.

Just a few weeks before, two police officers were stabbed to death at their home outside Paris by a man claiming allegiance to the Islamic State group.

President Emmanuel Macron's government has introduced legislation to tackle radical Islamist activity in France, a bill that has stirred anger in some Muslim countries.