Ahmed Jibril, veteran leader of a Damascus-based Palestinian faction that backs President Bashar al-Assad, has left the Yarmouk district of the Syrian capital after 12 days of clashes, Syrian rebels and Palestinian sources said on Saturday.

They said Jibril, head of the Popular Front for the Liberation of Palestine-General Command (PFLP-GC), departed Yarmouk with his son bound for the Mediterranean city of Tartous, a stronghold of Assad's minority Alawite community.

The move followed heavy fighting during which Syrian rebels, together with a brigade of Palestinian fighters known as Liwa al-Asifah (Storm Brigade), had gained ground in Yarmouk, home to thousands of Palestinian refugees, they said.

Syrian state television quoted a source in the PFLP-GC as denying reports that the rebels had taken over Yarmouk camp, but gave no further details.

The rebel and Palestinian sources said there had been a number of "qualitative defections" from the PFLP-GC ranks during the fighting.

Yarmouk, in southern Damascus, is part of an arc sweeping from the east to southwest of the Syrian capital where Assad's forces have been trying for several weeks to push back rebels from the gates of his power base.

Jibril's PFLP-GC has maintained strong ties to Assad throughout the 21-month uprising, unlike the militant Islamist Hamas movement whose Damascus-based officials - including leader-in-exile Khaled Meshaal - quietly pulled out of Syria as the mainly Sunni Muslim uprising against Assad gained momentum.