Thousands of civilians are fleeing from besieged enclaves on opposite ends of Syria as two major battles in the multi-sided war enters decisive phases, with hundreds of thousands of people trapped in the path of both assaults.
Air strikes had killed scores of people in eastern Ghouta, a war monitor said, and weary residents streamed out on foot for a second day on Friday, as Russian-backed government forces pressed their campaign to capture the last big rebel bastion near Damascus.
On another front, Turkish and allied rebel forces shelled the northern Kurdish-held town of Afrin heavily, killing at least 27 people and forcing 2500 people to flee, the Syrian Observatory for Human Rights war monitor said.
The Kurdish YPG militia defending Afrin said it was battling the Turkish forces who tried to storm the town from the north.
The two offensives, one backed by Russia and the other led by Turkey, have shown how Syrian factions and their foreign allies are aggressively reshaping the map of control after the defeat of Islamic State's self-proclaimed caliphate last year.
The Syrian war entered its eighth year this week having killed half a million people and driven more than 11 million from their homes, including nearly 6 million who have fled abroad in one of the worst refugee crises of modern times.
The government launched its offensive on eastern Ghouta a month ago, and Turkey began its cross-border assault in Afrin in January.
In both cases, hundreds of thousands of civilians have been trapped inside encircled pockets on the battlefield.
Backed by Russia and Iran, government forces have thrust deep into eastern Ghouta on the capital's outskirts, splintering the rebel enclave into three separate zones.
The United Nations believes up to 400,000 people have been trapped in the Ghouta's satellite towns and farmland, short of food and medicine.
For the first time in the month since the government unleashed the Ghouta offensive, one of the deadliest of the war, residents are fleeing in their thousands, carrying children and belongings on foot to government positions.
An estimated 12,000-16,000 people had left eastern Ghouta in recent days, while fighting in the Afrin region had reportedly displaced more than 48,000, said Linda Tom, a spokeswoman for the UN humanitarian affairs office in Syria.
The Syrian army and allied forces have recaptured 70 per cent of the territory that was under insurgent control in the enclave, it said on Friday.
The Observatory said air strikes in eastern Ghouta killed 80 people, including 14 children, in the towns of Kafr Batna, Saqba and Harasta on Friday.
Russian news agencies reported that more than 4000 people had come out on Friday.
Turkey wants to crush the YPG which it views as an extension of the Kurdistan Workers' Party (PKK), which has waged an insurgency in Turkey.
The US views the YPG as a valuable partner in its war against IS in Syria.
The Kurdish-led civil authority of Afrin said Turkey ramped up air and artillery strikes on the densely populated town this week, killing dozens of people in the past two days.
In a statement, it said the main water supply was cut, and accused Ankara of trying to make residents leave.