Russia has said that it supports international peace envoy Lakhdar Brahimi, but insists that President Bashar al-Assad's exit cannot be a precondition for a deal to end the country's conflict.

Up to 60,000 Syrians have been killed during the 21-month revolt and world powers are divided over how to stop the escalating bloodshed.

Government aircraft bombed outer districts of Damascus after being grounded for a week by stormy weather.

The Russian Foreign Ministry reiterated calls for an end to violence in Syria following talks yesterday in Geneva with the US and Mr Brahimi.

There was no sign of a breakthrough.

Mr Brahimi said the issue of President Assad, who the US, European powers and Gulf-led Arab states insist must step down to end the civil war, appeared to be a sticking point.

Russia's Foreign Ministry said: "As before, we firmly uphold the thesis that questions about Syria's future must be decided by the Syrians themselves, without interference from outside or the imposition of prepared recipes for development."

Russia has been Mr Assad's most powerful international backer.

It joined with China to block three Western- and Arab-backed UN Security Council resolutions aimed to pressure him or push him from power.

President Assad can also rely on regional powerhouse Iran.

Russia called for "a political transition process" based on an agreement by foreign powers last June.

Mr Brahimi, who is trying to build on that agreement, has met three times with senior Russian and US diplomats since early December and met President Assad in Damascus.

Russia and the US disagreed over what the June agreement meant for Mr Assad.

The US said it sent a clear signal he must go and Russia contended that it did not.

Qatar today made a fresh call for an Arab force to end bloodshed in Syria if Mr Brahimi's efforts fail, according to the Doha-based al Jazeera television.