The body representing Muslims in France has called on the country's 2,500 mosques to condemn "all forms of violence or terrorism" in prayers this Friday.
The call comes days after a string of coordinated attacks across Paris killed 129 people.
The message will condemn such acts "unambiguously", the French Muslim Council (CFCM) said.
"French Muslims want to proclaim their indestructible attachment to the republican pact and the values which have formed France," a spokesman for the group told French paper Le Figaro.
The Great Mosque, France's most important Muslim place of worship, also called on all French imams to lead the faithful in Friday prayers for the victims of the attacks on the Bataclan theatre, the Stade de France and several restaurants around the capital last Friday.
The mosque's rector Dalil Boubakeur voiced "horror" at the "unspeakable acts" which had targeted "absolutely innocent" Parisians.
"We, Muslims of France, can only insist on the need for national unity in opposing this misfortune which has afflicted us and which attacks indiscriminately," he said.
"We are all victims of this barbarity," he said.
It remains to be seen if all mosques will answer the CFCM's call for a unified sermon.
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The suicide bombers behind Friday's attacks on the national stadium, a packed music venue and bars and restaurants were "people who call themselves Muslims but who should, by rights, be called barbarians", Boubakeur said.
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State of emergency
The Grand Mosque had earlier urged Muslims to gather at the mosque to say "No to terror" and "We are all Paris!", but the rally, scheduled for Friday, was cancelled as the country remained in a state of emergency.
The lower house of the French parliament on Thursday voted to extend the state of emergency for three months, following advice from President Francois Hollande.
Bernard Cazeneuve, the French interior minister, said the state of emergency meant a more rigorous crackdown on those "who preach hatred in France", including through expulsions and the "dissolution of radical mosques".
"I didn't wait for the state of emergency to track down radical imams who preach hatred and to address places of worship where they preach that hatred," Cazeneuve said in an interview with France 2 TV.
Source: Al Jazeera and agencies