Jaish al Islam said to have given up arms in return for safe passage.
Reports say a deal has been struck to remove critically injured people from the last rebel bastion near Damascus, which is surrounded by the Syrian army.
Thousands flee expected final assault as rebels lose all but one strongpoint in region close to capital.
For the second successive day, thousands of rebel fighters and their families are leaving eastern Ghouta as part of a surrender deal with the government
Syrian opposition Civil Defense known as While Helmets released footage showing widespread destruction in Douma, eastern Ghouta, caused by ongoing fighting between the Syrian army and the rebels.
The Syrian leader met government troops fighting the remaining rebel groups in eastern Ghouta
Assad visits troops in Ghouta as civilians flee the besieged region in their tens of thousands.
Syrian forces are trying to reclaim the region
Backed by Russia and Iran, government forces have thrust deep into Eastern Ghouta, splintering the area into three separate enclaves and trapping up to 400,000 people
Syrian government tanks have advanced on Hammouriyeh. Whilst the regime pushes to reclaim the rebel held Ghouta enclave, the UN is calling for urgent civilian evacuations.
The UN says the evacuation of civilians from eastern Ghouta is expected today, as the US warns there must be a ceasefire in Syria.
The Syrian army intensified its onslaught in eastern Ghouta on Saturday with advances that a war monitor and state media said had splintered the enclave, though a rebel official denied this.
The footage shows 13 men getting onto a bus and arriving at a crossing point where they hand themselves over to authorities.
Akram Abu al-Fawz, from eastern Ghouta, has exhibited internationally and attracted followers worldwide with his unusual art, which he shares on Facebook.
The convoy was carrying food that could not be offloaded on Monday when fighting forced an earlier delivery to leave early
Medics report a chlorine gas attack in Eastern Ghouta, just hours after an aid convoy left the area.
The Damascus suburb is home to around 400, 000 people and has been subject to an extensive bombing campaign by forces loyal to President Assad.
No deal yet on evacuation of wounded or more aid convoys, but UNICEF says Damascus may allow a convoy with aid for 180,000 of the 400,000 civilians trapped in the region.
Civilians too frightened to use five-hour daily ceasefires to flee, and window too short to allow aid to get through says UN.
Damascus denies using chemical weapons but a UN investigation says North Korea shipped equipment that could have been converted
Foreign policy chief Federica Mogherini says "every single minute we wait there are people dying."
Euronews spoke to a local doctor and aid worker about the plight of civilians, and about their faith in prospects for desperately-needed relief.
Air strikes by the Syrian government on the rebel-held enclave are reported to have continued despite a ceasefire resolution passed by the UN Security Council.
This video shows scenes of injury, destruction and death.
UNICEF said it had no words left for what's been happening in eastern Ghouta. The only way to understand is to see it. (The scenes are disturbing and upsetting.)
Aid groups say Russian and Syrian warplanes have pounded the last rebel enclave for a fifth straight day hitting civilian targets