Syrian government forces have bombarded eastern Ghouta anew in an effort to slice the rebel enclave in two, intensifying a campaign to deal the opposition its biggest defeat since 2016.
The Syrian Observatory for Human Rights war monitor said pro-Syrian government forces had managed to bring the strip of territory linking the north and south of what remains of rebel-held eastern Ghouta within firing range, effectively bisecting the densely populated region on the outskirts of Damascus.
The Syrian government onslaught on eastern Ghouta, which began more than two weeks ago, has become one of the fiercest campaigns of a war now entering its eighth year, with bombardment killing hundreds of people.
Live footage broadcast by Syrian state TV from the outskirts of the town of Mesraba earlier on Wednesday showed enormous clouds of smoke rising into the sky. The sounds of explosions and jets could be heard.
A state TV correspondent said militant defences in the town were being struck by "preparatory fire" in advance of a planned infantry assault.
Capturing Mesraba would be a major step towards severing the northern half of Ghouta, including its biggest town Douma, from the southern part. Government forces have seized more than 50 per cent of the territory so far.
Civilians have been fleeing frontline areas into Douma and hiding in cellars, with aid workers saying many children had told them they had not seen daylight in 20 days.
"It's bad in the basement, but it's better than the bombing," Adnan, 30, a Douma resident who has been sheltering below ground with his wife and two-year-old daughter together with 10 other families, told Reuters by telephone.
The United Nations says 400,000 people are trapped and asked the government to commit to a ceasefire on Thursday to allow more aid in.