International envoy Lakhdar Brahimi pursued mediation efforts in Damascus on Tuesday, December 25 but there was no pause in the bloodletting as Syrian Christians marked a bleak Christmas Day with prayers for peace, Reuters said.

Brahimi met some dissidents who are tolerated by Assad but rejected by the mainstream opposition and by rebels fighting to oust him, a day after he held talks with the Syrian president.

There was no word on any progress in the U.N.-Arab League' envoy's drive to end violence that has intensified in recent months as Assad uses airpower and artillery against rebel gains.

Raja Naser, secretary general of the National Coordination Body, said after meeting Brahimi that the envoy planned a week of meetings in Damascus and would stay until Sunday.

"There is still a lot of concern but there is also great hope that these meetings with other Syrian officials will result in some agreements or positive developments," he said.

But most opposition groups appear frustrated with Brahimi's quest for a deal on a transitional government. He has not clarified any role for Assad, whose foes say he must simply go, arguing that too much blood has been shed for any other outcome.