France has lifted its security alert status to the highest level after a knife-wielding Tunisian man killed three people in a church in the city of Nice.
The victims, including two women, died on Thursday when the armed immigrant went on a beheading and throat-slitting attack before he was overpowered and arrested.
A defiant President Emmanuel Macron said France had been subject to an Islamist terrorist attack, and promised to deploy thousands more soldiers to protect important French sites, including places of worship and schools.
Speaking from the scene, he said France had been attacked “over our values, for our taste for freedom, for the ability on our soil to have freedom of belief”.
“And I say it with lots of clarity again today: we will not give any ground,” Mr. Macron declared.
France’s chief anti-terror prosecutor Jean-François Ricard said the attacker was born in 1999, and had recently entered France from Italy.
A Tunisian security source told Reuters the suspect’s name was Brahim Aouissaoui.
Mr Ricard said one of the women had her throat cut. A police source earlier told Reuters that the victim had been beheaded.
The attacker reportedly arrived in Italy by reaching the Mediterranean island of Lampedusa on September 20, and then travelled to Paris on October 9.
The Associated Press quoted Italian media reports as saying the attacker spent two weeks in quarantine on a ship off the eastern coastal town of Bari in September, before being expelled from Italy and heading to Paris.
The display of cartoons of Prophet Mohammed in France has sparked anger in the Muslim world.
Over a week ago, a French schoolteacher was beheaded shortly after showing his students a cartoon depicting the holy prophet.