The Syrian regime seized control on Saturday of a road linking the town of Douma with Harasta in Eastern Ghouta, effectively splitting the enclave in three, said the Syrian Observatory for Human Rights.
"Regime forces have divided Eastern Ghouta into three parts -- Douma and its surroundings, Harasta in the west, and the rest of the towns further south," the Britain-based war monitor said.
The army captured a road linking the town of Douma with Harasta further west, and also captured the town of Misraba, the Observatory explained.
An AFP correspondent inside Douma said shelling and air strikes were rocking the town on Saturday.
Besieged by regime forces since 2013, Ghouta is the last remaining rebel-held area near the capital.
Keen to secure Damascus, regime troops and allied militia have been closing in on the enclave since February 18 and have overrun more than half of it.
More than 975 civilians, over 250 of them children, have been killed and hundreds more wounded, according to the Observatory.
Jaish al-Islam and Failaq al-Rahman, the two main rebel groups in eastern Ghouta, could not be immediately reached for comment. They have said in recent days that they had staged counter attacks taking back some lost positions.
The Eastern Ghouta offensive follows the pattern of previous assaults on rebel strongholds, deploying massive air power and tight sieges to force insurgents to accept “evacuation” deals.
These involve rebels surrendering territory in exchange for safe passage to opposition areas in northwest Syria, along with their families and other civilians who do not want to come back under Bashar Assad’s rule.
The intensity of the regime’s attack on Eastern Ghouta, which suffers acute shortages of food and medical supplies, has drawn Western condemnation and demands by UN aid agencies for a humanitarian halt in fighting.
The United Nations estimates that some 400,000 people are trapped in the enclave.
“Living conditions are harsh... Shop owners and traders are sending their workers to the shelters to sell food for three times their price before the offensive,” said a man in Saqba who identified himself as Abu Abdo in a voice message.
Aid agencies have tried to deliver aid into Eastern Ghouta, but they have only been able to bring in a portion of the amount they wanted.
A convoy was unable to finish unloading on Monday because of continued fighting, bringing in the remaining undelivered food parcels on Friday despite bombardment nearby.
However, UN agencies said most medical supplies had been stripped from the convoy by Syrian regime officials and added that the food supplies brought in were insufficient.
