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.
"Negotiations are ongoing, but they've been delayed by internal differences in the rebel group," Rami Abdel Rahman, head of the Syrian Observatory for Human Rights, told AFP. 
"Jaish al-Islam's commanders are divided and some are opposed to a deal," he said. 
The deaths of five Syrian soldiers shot by snipers late Saturday was linked to efforts by hardliners to "sabotage" any kind of reconciliation, he added.
A potential "reconciliation deal" would see Jaish al-Islam disarm but stay in Douma, according to the Britain-based monitor.
It would also provide for the deployment of Russian military police and the return of regime institutions and basic services like water and electricity. 
The Syrian army, however, would not enter.
Rebels who refuse to lay down their arms would be bussed out, the Observatory said. 
Russian officials and a local negotiating committee from Douma are expected to meet in the coming days, committee members told journalists. 
"The ongoing negotiations with Russia are to stay in Douma, not to leave it," Jaish al-Islam spokesman Hamza Bayraqdar said late Sunday.
The Syrian government has used sieges and heavy bombardment followed by evacutation deals to recapture swathes of rebel-held territory.
The regime smashed the Ghouta enclave into three isolated pockets before it sought separate evacuation deals for each.
But with talks suspended, the fate of Douma residents remains uncertain. 
More than a thousand people fled on Sunday to areas controlled by the regime, according to Syrian state media.
The exodus came after 15,000 people left the Douma pocket in the five previous days, according to the Observatory. 
"I'm leaving because I'm sick, weak, because there are shortages and hunger," 53-year-old Fayez Ali Thaljah told AFP as he left. 
Others categorically refuse to leave, even though they have no illusions about life under government control. 
"I've spent my whole life here and lived the revolution. My father died here. How could I abandon his grave?" said 30-year-old Abu Ayman. 
"But I could never live alongside regime forces."