Thousands of civilians have fled advances by Syrian government forces in eastern Ghouta over the last two days, a war monitor and a resident said on Sunday, as Damascus wages an offensive to crush the last major rebel enclave near the capital.
A commander in the military alliance that backs President Bashar al-Assad said government forces needed to advance just a few more kilometres (miles) into the enclave to split it in two.
A UN humanitarian official said 400,000 people in eastern Ghouta were being subjected to unacceptable "collective punishment", and called for the implementation of a 30-day ceasefire demanded by the UN Security Council.
With the war entering its eighth year, capturing the eastern Ghouta area would be a major victory for Assad, who has steadily recovered control of rebellious areas with military support from Russia and Iran.
The multi-sided Syrian war, which has killed hundreds of thousands of people since 2011, has escalated on several fronts this year, as the collapse of Islamic State has given way to other conflicts between Syrian and international parties.
Turkey, backed by allied Syrian militias, has gained ground in recent days against the Kurdish YPG militia in an offensive it is waging in north-western Syria. The Syrian Observatory for Human Rights (SOHR) said the advances threaten to encircle Afrin city, where one million people are estimated to live.
The eastern Ghouta offensive is one of the deadliest of the war. SOHR says shelling and air strikes have killed 659 people there since February 18, while rebel shelling of Damascus has killed 27.
Orient TV, which supports the opposition, said advances by pro-Assad forces had triggered large-scale displacement.
One resident estimated that thousands of people were on the move and seeking shelter in areas further from the frontlines.
SOHR, a UK-based organization which reports on the war, estimated that between 300 to 400 families - roughly several thousand people - had fled areas seized by government forces since Saturday.
The pro-Assad commander said civilians were fleeing into to the town of Douma. "There are about three and a bit kilometres (to go) and they will cut (eastern Ghouta) in two," the commander told Reuters.
Gunfire was audible during a broadcast by a Syrian state television journalist from a position he said had been captured by the advancing forces.
The Syrian army said it had been attacking rebel positions for the last two days in response to shelling of Damascus and had recovered control of farmland and towns.
‘More fighting, more death’
With no sign of meaningful Western pressure to halt the offensive, eastern Ghouta appears on course to meet the same fate as other rebel areas retaken by Assad.
UN regional humanitarian coordinator Panos Moumtzis said violence has escalated in eastern Ghouta, and also noted that mortars fired into Damascus had killed and injured scores of civilians.
"Instead of a much needed reprieve, we continue to see more fighting, more death, and more disturbing reports of hunger and hospitals being bombed. This collective punishment of civilians is simply unacceptable," Moumtzis said in a statement.
A UN official in Syria told Reuters a humanitarian convoy carrying life-saving supplies from UN and other aid agencies would not enter eastern Ghouta as had been planned on Sunday, citing a lack of permission.
Russia has called for daily, five-hour humanitarian ceasefires to allow for aid deliveries and evacuations of civilians and wounded. No aid has been delivered however, and the US State Department has called the Russian plan a "joke.”
The Russian military said militants had imposed a curfew to prevent civilians from leaving through a humanitarian corridor during the truce, Interfax news agency reported. Rebel officials have consistently denied stopping civilians from leaving.
Moumtziz also expressed concern about the situation in Afrin, the Kurdish region that has been under Turkish assault since January, saying there were "disturbing reports" on civilian deaths and injuries, and restrictions on civilian movement.
Turkish forces, supported by Syrian rebel groups, seized the town of Rajo on Saturday, and Turkey's prime minister said they were advancing towards Afrin city "step by step.”
The SOHR said Turkish forces had advanced to within 12 km (7 miles) of Afrin.
Turkey has rejected Western calls for it to suspend the Afrin assault in line with the UN ceasefire, which does not apply to Islamic State, al Qaeda and groups associated with it, or other groups deemed terrorists by the Security Council.
Turkey views the YPG as an extension of the Kurdistan Workers' Party (PKK), which has fought a three-decade insurgency in Turkey and is deemed a terrorist group by the United States, the European Union and Turkey. The YPG has been an important ally for the United States in the fight against Islamic State.