Talks over the fate of Douma, the final rebel-held zone in Syria’s Eastern Ghouta, have stalled over divisions within the Islamist faction that holds the area, a monitor said Monday.

Battered by a five-week regime offensive, two major rebel factions have agreed in recent days to leave other pockets of Ghouta for opposition-held territory in the country’s northwest after talks with Russia.

Negotiations are now underway with Islamist group Jaish al-Islam, which controls Ghouta’s largest town, Douma.

Heavy fighting and strikes on the town have largely subsided, but talks have yet to bear fruit.