Three people have died in a knife attack at a church in Nice, in what French President Emmanuel Macron said was an “Islamist terrorist attack”.
He said France would not surrender its core values after visiting the Notre-Dame basilica in the southern city. More troops are being deployed to protect churches and schools.
In Nice, one elderly victim was “virtually beheaded”, officials said. Another woman and a man also died.
A male suspect was shot and detained.
Nice Mayor Christian Estrosi spoke of “Islamo-fascism” and said the suspect had “repeated endlessly ‘Allahu Akbar’ (God is greatest)”.
Two other attacks took place on Thursday, one in France and one in Saudi Arabia.
A man was shot dead in Montfavet near the southern French city of Avignon after threatening police with a handgun.
Separately, a guard was attacked outside the French consulate in Jeddah in Saudi Arabia. A suspect was arrested and the guard taken to hospital.
Anti-terror prosecutors have opened a murder inquiry into the attack in Nice, and France has raised its national security alert to its highest level.
“If we are attacked once again it is for the values which are ours: the freedom, for this possibility on our soil to believe freely and not to give in to any spirit of terror,” President Macron said.
“I say it with great clarity once again today: we won’t surrender anything.”
Meanwhile, Mr Estrosi compared the attack to the recent murder of teacher Samuel Paty, who was beheaded close to his school outside Paris earlier this month.
Police have not suggested a motive for the attack in Nice. However, it follows days of protests in some Muslim-majority countries triggered by President Macron’s defence of the publication of cartoons that depicted the Prophet Mohammed. There have been calls in some countries for a boycott of French goods.
Two of those who died were attacked inside the church, the elderly woman and a man who was found with his throat cut, reports said.
A woman managed to flee to a nearby cafe after being stabbed several times, but died later.
It later emerged that a witness had managed to raise the alarm with a special protection system set up by the city.
Chloe, a witness who lives near the church, told the BBC: “We heard many people shouting in the street. We saw from the window that there were many, many policemen coming, and gunshots, many gunshots.”
Tom Vannier, a journalism student who arrived at the scene just after the attack, told the BBC that people were crying on the street.
Four years ago Nice was the scene of another terror attack, when a Tunisian drove a truck into crowds celebrating Bastille Day on 14 July, killing 86 people.