Three people have been killed in an apparent Islamic terrorist attack in the French city of Nice, local police have reported.

The knife attack, which left one female victim beheaded, took place in a local Catholic church. Christian Estrosi, the city’s Mayor, said that all evidence indictated a “terrorist attack at the heart of the Notre-Dame basilica”, and that it was an act of “islamofascism”.

The suspect, who was captured alive and detained shortly after the incident, was reported to have “repeated non-stop” the Arabic phrase “Allahu Akbar”, which translates to “Allah is greatest”, while being arrested at the scene.

The attack comes shortly after another Islamist murder in France earlier this month, where a school teacher was beheaded for giving a class on free expression that included pictures of Islam’s founder Muhammad.

Since this murder, French President Emmanuel Macron has spoken out in defence of free speech and the right to mock religions and ideologies. The President’s comments have sparked mass protests and calls to boycott French-made products in several Muslim-majority countries.

The latest attack came after a screed by Iran’s supreme leader, the Ayatollah Khomeini, who blasted Macron’s comments earlier this week.

“Ask your president why he supports insulting God’s messenger in the name of freedom of expression. Does freedom of expression mean insulting, especially a sacred personage?”, the religious figurehead said.

“Without question this is a very serious new challenge that is impacting our country,” said French Prime Minister Jean Castex.

A murder inquiry has been opened, and a minute’s silence out of respect was held in the French National Assembly. The interior Minister has said he will be organising a crisis meeting in Paris shortly.

Previously in 2016, Nice was the target of one of Europe’s deadliest Islamic terror attacks, when a Tunisian Islamist drove a truck into French crowds celebrating their national holiday of Bastille Day. That attack left 86 dead and hundreds injured.