PARIS – At least three people have been killed in a knife attack on a Catholic church in central Nice, on the French Riviera, the city’s mayor Christian Estrosi said on Thursday.

The attacker has been shot and detained by police, Estrosi said, adding that “everything points to a terrorist attack at the heart of the Notre Dame basilica.”

The attack comes two weeks after a 47-year-old teacher, Samuel Paty, was beheaded by an extremist Islamist outside his school near Paris. Paty had shown a caricature of the prophet Muhammad to his pupils during a discussion on freedom of speech.

Images of the prophet are considered deeply offensive by many Muslims and are widely seen as taboo in Islam.

Following the brutal murder, French President Emmanuel Macron pledged that the country would “not give up its cartoons.” His comments and support of the teacher have sparked a furious reaction across the Muslim world.

“Thirteen days after Samuel Paty, our country cannot be satisfied with laws of peace to annihilate Islamofascism,” Estrosi said in a series of Twitter posts.

He added that he had spoken on the phone with Macron, who was en route to the city.

He said in footage posted to his Twitter account that one of the fatal victims was a woman who was beheaded, and that the perpetrator, who was seriously injured during his arrest by the municipal police, was repeatedly shouting “Allahu Akbar” (‘God is greatest’).

“Nice is once again the victim of Islamofascism. My first words are of compassion. We are wounded in our hearts to see that our city has again been targeted. I would like to say to all the families of the victims of this savage, how much we are by your side,” he said.

The assailant was taken down within minutes after a witness sounded an alarm.

“There is no doubt about the motive of the act,” Estrosi said. “An act in which it appears, for at least one victim inside the church, that (the assailant) chose the same method as with this poor teacher.

“An absolute horror, but an absolute symbol as well. This must lead us to no longer consider that it is with the laws of peace in our country that we will be able to annihilate Islamofascism.”

He thanked the police and first responders.

“There is emotion, and there is compassion. There is rage, and there is anger,” he said, adding that “we no longer have the right to retreat from anything.”

The Anti-Terrorist Prosecutor’s Office has opened an investigation for “murder with terrorist purposes,” among other charges.

After a minute’s silence in the National Assembly, Prime Minister Jean Castex and Interior Minister Gerarld Darmanin left the chamber for a “crisis cell.”

The mayor spoke with Macron, who has traveled to the scene of the attack.

The events took place at 9:00 am in a city that was already the scene in 2016 of an Islamist attack that caused 86 deaths after a truck ploughed through a crowd celebrating France’s national Bastille Day.