French authorities said Tuesday they would close a Paris mosque in a clampdown on radical Islam that has yielded over a dozen arrests following the beheading of a teacher who had shown his pupils cartoons of the Prophet Mohammed.

The mosque in a densely-populated suburb northeast of Paris had published a video on its Facebook page days before Friday's gruesome murder, railing against teacher Samuel Paty's choice of material for a class discussion on freedom of expression, said a source close to the investigation.

Muslim leaders gathered ouside Paty's school to offer condolences and distance their religion from the atrocity
Muslim leaders gathered ouside Paty's school to offer condolences and distance their religion from the atrocity AFP / Anne-Christine POUJOULAT

The interior ministry said the mosque in Pantin, which has some 1,500 worshippers, would be shut on Wednesday night for six months.

Interior Minister Gerald Darmanin has vowed there would be "not a minute's respite for enemies of the Republic".

The order came after police on Monday launched a series of raids targeting Islamist networks, mainly in the Paris region.

Police observe a minute's silence in Bordeaux in homage to history teacher Samuel Paty
Police observe a minute's silence in Bordeaux in homage to history teacher Samuel Paty AFP / Philippe LOPEZ

Paty, 47, was attacked on his way home from the junior high school where he taught in Conflans-Sainte-Honorine, 40 kilometres (25 miles) northwest of the capital.

A photo of the teacher and a message confessing to his murder was found on the mobile phone of his killer, 18-year-old Chechen Abdullakh Anzorov, who also posted images of the decapitated body on Twitter.

France teacher attack: Rallies held to support beheaded Samuel Paty
France teacher attack: Rallies held to support beheaded Samuel Paty AFPTV / June RACLET

Anzorov was shot dead by police.

Samuel Paty was attacked on his way home from the junior high school where he taught in a Paris suburb
Samuel Paty was attacked on his way home from the junior high school where he taught in a Paris suburb AFP / Anne-Christine POUJOULAT

Education Minister Jean-Michel Blanquer said Tuesday that Paty would be posthumously bestowed France's highest order of merit, the Legion of Honour, for having been "martyred" because of his profession.

The murder was preceded by a fierce online campaign against Paty and the school, led by the father of a schoolgirl who accused the teacher of disseminating "pornography" for showing a cartoon of the prophet naked.

Tens of thousands rallied across France on Sunday in solidarity with the murdered teacher
Tens of thousands rallied across France on Sunday in solidarity with the murdered teacher AFP / GEORGES GOBET

The school said Paty had given Muslim pupils the choice to leave the classroom.

The father who posted the video shared by the Pantin mosque is among 15 people arrested after the killing, along with a known Islamist radical and four members of Anzorov's family.

Darmanin accused the father and the radical of having issued a "fatwa" against the teacher.

IMAGESMarlène Schiappa, Deputy Minister for Citizenship meets French bosses from major social networks and platforms (Facebook Twitter, Google, Tiktok and Snapchat) as part of the "fight against cyber-Islamism", four days after the savage murder of a pro
IMAGESMarlène Schiappa, Deputy Minister for Citizenship meets French bosses from major social networks and platforms (Facebook Twitter, Google, Tiktok and Snapchat) as part of the "fight against cyber-Islamism", four days after the savage murder of a professor in Conflans-Sainte-Honorine. AFPTV / Lise BOLLOT

On Tuesday, the head of the Pantin mosque, M'hammed Henniche, said he had shared the video not to "validate" the complaint about the cartoons, but out of fear that Muslim children were singled out in class.

Four pupils suspected of accepting payment for pointing Paty out to his killer were also taken into custody Monday.

Junior interior minister Marlene Schiappa was to meet the French bosses of social media networks Tuesday to discuss bolstering the "fight against cyber-Islamism".

Paty's killing has drawn parallels with the 2015 massacre at French satirical magazine Charlie Hebdo, where 12 people, including cartoonists, were gunned down for publishing cartoons of Mohammed.

Tens of thousands of people took part in rallies countrywide on Sunday to honour Paty and defend freedom of expression, while Muslim leaders gathered at his school Monday to offer condolences and distance their religion from the atrocity.

French President Emmanuel Macron threatened that "fear is about to change sides" in the new anti-Islamist campaign.

Paty's beheading was the second knife attack since a trial started last month over the Charlie Hebdo killings.

In the September attack, two people were wounded outside the publication's former offices.

A silent march is planned for Conflans-Sainte-Honorine on Tuesday evening in homage to Paty, while parliament will observe a minute of silence in the afternoon.

Macron will attend an official homage with Paty's family Wednesday at the Sorbonne university.

Blanquer added that schools countrywide will observe a minute's silence for Paty when pupils return after the autumn break, and a special lesson on the recent events will be taught in all classes.

Justice Minister Eric Dupond-Moretti on Tuesday denied there had been any failure on the part of intelligence services.

Meanwhile, Paris prosecutors said they had opened an investigation into a French neo-Nazi website hosted abroad that republished the photo of Paty's decapitated corpse posted to Twitter by the killer.