(Adds Hollande speaking to Merkel, Cameron)
PARIS, Aug 16 (Reuters) - France's foreign minister said on Friday the escalating tension in Egypt risked playing into the hands of radical groups and urged all sides to do their utmost to defuse the tension.
Defying criticism from major Western allies, Egypt's army-backed government said on Thursday it would turn its guns on anyone who attacked the police or public institutions.
The Muslim Brotherhood called for a nationwide march of millions on Friday to show anger at a ferocious security crackdown on Islamists in which hundreds were killed.
"Given that Egypt was the guarantor of peace in the region, it's even more worrying," Laurent Fabius told RTL radio. "Maximum restraint must be shown otherwise the risk is that extremist groups take advantage of the situation and that would be extremely serious."
French President Francois Hollande was due to speak to German Chancellor Angela Merkel and British Prime Minister David Cameron later on Friday to discuss events in Egypt, a French official said.
France and Britain requested a U.N. Security Council meeting on Thursday evening. The 15-member group urged all parties to end the violence and exercise maximum restraint after hundreds of people were killed when troops and police crushed protests seeking the return of deposed President Mohamed Mursi.
Fabius said everything had to be done to avoid civil war and get all sides back to the negotiating table.
"There must be a winding down of the tension. The authorities must make gestures and demonstrators also have a duty to demonstrate peacefully," Fabius said. (Reporting by John Irish and Julien Ponthus; Editing by Alistair Lyon)