Air strikes killed dozens of civilians in Eastern Ghouta on Saturday and forced thousands more to flee, as Syrian troops pressed their blistering assault on the last rebel stronghold near Damascus.
The latest deaths brought the toll for the nearly month-old offensive to more than 1,400, with world powers still unable to stop one of the devastating conflict's worst crises.
More than 10,000 civilians reached army positions on Saturday, state media said.
The Syrian Observatory for Human Rights, a UK-based monitoring group, said 30 people were killed in an air strike as they were gathering to leave the rebel-held town of Zamalka on Saturday, a day after at least 96 civilians were killed in air strikes.
Most of Friday's deaths were in the town of Kafr Batna, which was seized by government forces on Saturday, the Observatory said.
Syria's war enters its eighth year with another deadly assault also unfolding in the north, where Turkish-led forces pressed an operation to seize the Kurdish-majority region of Afrin.
More than 150,000 people have fled the town in the last few days, a senior Kurdish official told Reuters. Bombing of the city of Afrin on Friday killing 43 civilians, a third of them killed in a deadly strike on a hospital.
On the edge of Ghouta, a sprawling semi-rural area within mortar range of central Damascus, thousands of civilians were streaming out of destroyed towns, carrying scant belongings in bags and bundles.
The governor of rural Damascus, Alaa Ibrahim, said the government was setting up new centres due to the massive crowds.
Syria's envoy to the UN Bashar Al Jaafari said 40,000 people fled Ghouta on Thursday, the first day of a sudden exodus that appeared to have caught the government flat-footed.
Long lines formed outside the public bathrooms at a government centre on the edge of Eastern Ghouta, and displaced families complained of a lack of access to water or mattresses.
The Syrian army in a message broadcast on state television urged all residents to use "corridors" it had established to leave the enclave, saying it had recaptured 70 per cent of rebel territory.
The ground offensive pressed by Syrian troops and allied militia has splintered Eastern Ghouta into three pockets, each held by a different faction.
Those three Islamist groups said Friday they would be willing to negotiate directly with Russia on a ceasefire for Ghouta, but did not mention talks with the Syrian government.
Their statement came hours after UN special envoy for Syria, Staffan de Mistura, said talks were ongoing between Russia and one of the groups, Jaish Al Islam.
That negotiations track had already produced six days of calm for Ghouta's largest town of Douma, he said.
Douma has also seen deliveries of food, and hundreds of civilians have been bussed out as part of medical evacuations.
Syrian President Bashar Al Assad has in recent months recovered swathes of territory lost at the beginning of the conflict and Ghouta was one of his key remaining targets.
An exodus of similar proportions was under way hundreds of kilometres to the north in the city of Afrin, where Kurdish forces have been nearly encircled by Turkish troops.
The Observatory said said a Turkish strike on Friday hit Afrin's hospital, killing 16 civilians, including two pregnant women.
"There was bombing on the city during the day that got close to the hospital, but this evening it was directly hit," Serwan Bery, co-chair of the Kurdish Red Crescent, told AFP.
"It was the only functioning hospital in Afrin city," he said.
The deadly strike brought to 43 the number of civilians killed in the town on Friday, the Observatory said.
Turkey's military denied hitting the hospital, saying on Twitter that its operation in Afrin "is carried out in such a way as to not cause any harm to civilians."
The UN said it was worried the forces staying inside were not allowing civilians to flee, as that would leave them more exposed to Turkey's superior firepower.
Ravina Shamdasani, spokesman for the UN's Rights Office decried "reports that civilians are being prevented from leaving Afrin city by Kurdish forces ... (and) are being held to be used as human shields."