At least 30 people have been killed in heavy air strikes on the last rebel-held town in Syria's Eastern Ghouta region, activists and rescuers say.
The official Sana news agency cited a military source as accusing Jaysh al-Islam of "thwarting" the deal by refusing to allow "state institutions" back into Douma and release prisoners it was holding.
However, Jaysh al-Islam political official Mohammad Alloush told al-Hadath TV that the group did not want to "close the door that can lead to sparing the blood of civilians and reaching a peaceful situation".
More than 1,600 people are reported to have been killed and thousands injured since the government and its allies launched an offensive in mid-February to retake the Eastern Ghouta, which was the last major rebel stronghold near Damascus.
Last month two other factions - Faylaq al-Rahman and Ahrar al-Sham - agreed the evacuation of some 50,000 rebels and civilians living in Eastern Ghouta towns under their control to the mainly rebel-held northern province