As government forces have steadily reclaimed towns and villages in eastern Ghouta, they have given rebels and men of fighting age the choice of accepting amnesty and serving in the Syrian military, or relocating to rebel-held areas in northern Syria. The government says it is restoring security to Damascus, which was regularly shelled from eastern Ghouta during the war.
Syria's army had on Saturday vowed to finish off rebels in Douma.
A council member of opposition-controlled Douma on Sunday denied earlier reports by the Syrian military media that the Jaish Al Islam faction had agreed to surrender the town to the regime.
Jaish al-Islam counts around 10,000 fighters, according to the Syrian Observatory for Human Rights.
The pan-Arab al-Mayadeen TV said the agreement of Douma could be included in the next hours. The US military has not said if the IED was in a building, a vehicle or buried in the road.
They reportedly include 1,100 Faylaq al-Rahman fighters and their relatives who left Douma late on Sunday.
A State Department spokesperson said the agency "continues to work with the worldwide community, members of the Coalition, and our partners on the ground to provide much needed stabilization support to vulnerable areas in Syria".
Douma is a stronghold of the powerful Jaish al Islam opposition group.
Elsewhere in Syria, Russian and Syrian military officers told rebels in Eastern Qalamoun, about 25 miles northeast of Damascus, they must accept regime rule or leave.
Douma has been besieged by government forces since 2013.
Russia's military also said Sunday that a preliminary agreement has been reached on the evacuation of Army of Islam fighters. Maj.
Trump reportedly ordered the funding to be frozen after reading a report about it in The Washington Post, U.S. officials told Reuters.
The government was not party to the negotiations over Douma, which were conducted between Russian Federation and the Army of Islam.
Humanitarian cases would be allowed to leave on Monday, according to Abdelaziz.
Hundreds of residents are believed to require care for war wounds and medical conditions exacerbated by the siege.
Local activists say over 100,000 civilians are trapped inside Douma, which has suffered catastrophic damage.
The aid package being suspended was a priority of now-fired Secretary of State Rex Tillerson, who had emphasized the importance of a strong American presence in Syria as a way to stabilize the region and combat Islamic State-backed terrorists from regaining strength.
Government forces taking back most of eastern Ghouta reopens a major network of roads and highways that link Damascus with other parts of the country that have been closed since 2012 when rebels captured eastern suburbs of the capital.
Tens of thousands of other civilians have fled to regime-held territory.
At least 14 civilians were killed by air raids in Idlib province on Saturday, a civil defence official said.
Accordingly, Trump's sudden prediction that USA forces would withdraw from Syria "very soon", caused consternation at the Pentagon, the State Department, the National Security Council, and the editorial pages of pro-war publications like the Washington Post.