Syria's army cut the last main supply route for a rebel bastion east of Damascus Sunday, further tightening a crippling siege on the area, a monitor and state media said.

"The regime has cut off the last main road for rebels leading out of Eastern Ghouta," the main opposition stronghold in Damascus province, said Syrian Observatory for Human Rights chief Rami Abdel Rahman.

He said army units had taken over almost all of the village of Maydaa, which lies along a road running east which rebels use to bring food and reinforcements into besieged neighbourhoods.