"The Army of Islam has taken the decision to stay put, but there is hope they will change their mind", said a Douma-based opposition activist, who spoke on condition of anonymity for fear of reprisals.
Russian President Vladimir Putin, Syrian President Bashar al-Assad's main ally in the conflict, ordered daily five-hour ceasefires and the creation of a "humanitarian corridor" to allow civilians to leave Eastern Ghouta starting from February 28.
SANA news agency reported that 28 citizens abducted by Takfiri terrorists stationed in Eastern Ghouta were liberated late Monday by the Syrian Army in Erbin humanitarian corridor which was established to evacuate civilians stuck in the area.
The regime-controlled Syrian Central Military Media said 18 buses carrying 1,100 people, including 238 opposition fighters from different rebel factions, were getting ready Monday to leave the towns of Jobar, Zamalka and Arbeen toward Idlib.
One, implemented last week, saw hardline Islamist rebels from Ahrar al-Sham leave the battered town of Harasta in the west of the enclave.
Dozens of people had been waiting since early morning for the arrival of relatives and friends who were bussed out of Ghouta.
Douma-based activist Laith al-Abdullah told Al Jazeera that Faylaq ar-Rahman are trying to evacuate their extended family members now trapped in Douma - despite ongoing negotiations.
Some 110,000 people have fled into government-held territory, majority on foot or motorbike, through corridors opened up by the army and its Russian allies, according to state media.
Before the recent offensive, the suburb had an estimated population of 400,000. "We've missed them so much", said Abu al-Laith, who himself was evacuated 10 months ago from another Damascus district.
The Jaish al-Islam military spokesman, in an interview with al-Hadath TV, said Failaq al-Rahman had rejected a proposal to mount a shared defense of Ghouta and accused it of cutting water supplies needed to fill defensive trenches.
It had been under siege by government forces since 2013 and only the town of Douma, the most populous part of eastern Ghouta, remains under rebel control.
Russian President Vladimir Putin, seen with Assad, visited Syria in December 2017 and said some Russian troops would begin withdrawing from the country but has continued to provide military support to Assad's forces.
Syria's pro-government Al-Watan daily reported similar terms and said the parties had three days to study the offer.