A knife-wielding man has attacked a female police officer at a department outside Paris.
The 49-year-old victim died of her wounds, according to the local prosecutor's office which added that the attacker has been neutralised and later died of injuries he had received during detention.
The attacker was a 36-year-old man of Tunisian origin, police added.
Prime Minister Jean Castex, who visited Rambouillet after the attack, tweeted his condolences to the family of the murdered policewoman.
"The Republic has just lost one of its everyday heroines, in a barbaric gesture and infinite cowardice. To her loved ones, I want to express the support of the entire nation. To our security forces, I want to say that I share their emotions and indignation."
Castex also called the attack a terrorist act and said that the country's anti-terrorism prosecutor's department has launched an investigation into the incident.
French President Emmanuel Macron took to Twitter to say that his country will not surrender in the war on terror.
"She was a police officer. Stéphanie was killed in her police station in Rambouillet, in the district of Yvelines which has already seen its share of tragedy. The Nation stands with her family, colleagues and law enforcement. In the fight against Islamist terrorism, we will not yield anything."
French Interior Minister Gerald Darmanin has ordered to strengthen security measures at police stations and gendarmerie offices across the country following the attack in Rambouillet, BFMTV reported.
According to François Bersani, a spokesman for Unité SGP Police FO, the attacker cried "Allahu Akbar".
Reuters reported, citing a police source, that the attacker did not shout Islamist slogans during the assault.
However, terrorist motives cannot be ruled out in the Rambouillet knife attack, the Paris region president Valerie Pecresse told BFMTV.
Watch Sputnik's broadcast from the scene of the attack.