The government has launched what it calls an unprecedented action against “separatism” following several Islamist attacks in France this autumn, including the beheading of a teacher who had shown his class caricatures of the Prophet Mohammad.

Darmanin said 76 mosques out of the more than 2,600 Muslim places of worship had been flagged as possible threats to France’s Republican values and its security. Where suspicions are confirmed, the mosque will be closed down, he said.

“There are in some concentrated areas places of worship which are clearly anti-Republican,” Darmanin told RTL radio, “(where) imams are followed by the intelligence services and where the discourse runs counter to our values.”

Investigators will dig into the mosques’ financing and the background of imams deemed suspicious and search for evidence, among other things, of Koranic schools for young children.

President Emmanuel Macron has warned of the growing menace of ‘Islamist separatism’ and its challenge to the unity of the secular French republic. Core French values such as the freedom of belief, gender equality and the right to blaspheme are threatened in localised areas, he has said.

“Faced with this ill that is eating into our country, France has rallied with resilience, with determination,” the president wrote in a letter to the Financial Times newspaper in November.

The government’s crackdown has left some Muslims feeling increasingly alienated in their own country. Some Muslim leaders while backing the government’s fight against Islamism have warned it against inadvertently lumping an overwhelming majority of their faith with the “fomenters of hate”.