There was no immediate comment from the Army of Islam.
The Syrian government sent buses into Douma to transport fighters from the Faylaq al-Rahman group to the rebel-held province of Idlib, SANA state news agency reported.
Speaking about the humanitarian corridor with the checkpoint at Muhayam Wafedeen, the representative of the reconciliation center said that a total of 100 civilians left the area via this corridor on Sunday, bringing the total number of people who used it up to 29,330.
They threatened to storm the city if rebels did not surrender the last ground in the enclave in return for safe passage to insurgent-held territory.
The U.S. -led coalition ground offensive against ISIS has recently come to a halt, however, as Syrian Kurdish fighters flee the coalition to battle Turkish and Syrian rebel forces conducting their own self-proclaimed counterterrorism operation against U.S. -backed Kurds whom Ankara believes to be linked to the militant Kurdistan Workers' Party (PKK).
In the past few weeks, these deals have seen more than 46,000 people - fighters and civilians - board buses with scant belongings to be driven to the northwestern province of Idlib, which is largely outside government control.
"Our position is consistent and clear", he said.
A crushing government offensive under the cover of Russian airstrikes that began on February 18 has forced opposition fighters in most of eastern Ghouta to agree to evacuate and head to Idlib province.
The committee has been working on a deal to spare the city an assault by the encircling Syrian army and its allies. Russian representatives have played a role in negotiating local ceasefires and evacuations.
The departure Saturday from southern and western parts of eastern Ghouta comes as negotiations are still ongoing between Russian mediators and officials from the Army of Islam to evacuate Douma, but no deal has been reached so far with the rebel group which insists on staying in the town.
On Saturday the rebel group concluded a week-long evacuation of thousands of its fighters from areas it had controlled in other parts of the enclave. "We refuse to be forcibly displaced and demographic change in Eastern Ghouta". The town is one of the last around the capital to hold out against the government.
The surrender deal, brokered by Russian Federation, would mark a major defeat for opposition forces and an end to a bloody six-week government offensive that has killed hundreds of civilians and forced tens of thousands from their homes in Eastern Ghouta.
The sources confirmed that the deal was instead similar to the one reached in Qaboun and Barza, which stipulated the evacuation of fighters opposed to a deal reached with the Syrian regime, and their families to the north of Syria.
Syria's conflict has killed more than 350,000 people since 2011 and spiralled into a complex war involving world powers.