The killing of a female police employee in a Paris commuter town on Friday was an attack on the French Republic, Prime Minister Jean Castex said on Saturday.

The attacker, a French resident of Tunisian origin, stabbed the police administrative worker, a mother of two, at a police station in Rambouillet, just south of Paris. The attacker was shot dead by police. 

Authorities have not given a motive for the killing. President Emmanuel Macron said on Friday France had been the victim of a terrorist attack.

-Once again, the Republic has been attacked. Once again, the French state has been threatened. We will not let this go by- Castex said on Saturday, speaking to reporters from the southern city of Toulouse.

BFM TV said Castex would hold a meeting later on Saturday in Paris with other government ministers.

France's anti-terrorism prosecutor said he was leading the investigation 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".

There have been several attacks by Islamist militants in recent years in France

On Nov. 13, 2015, bombings and shootings at the Bataclan theatre and other sites around Paris killed 130 people, and in July 2016 an Islamist militant drove a truck through a crowd celebrating Bastille Day in Nice, killing 86.

Last October, a French schoolteacher was beheaded in Conflans, another commuter suburb near Paris, by a Chechen teenager who was then shot dead by police.