France has struck a compromise with Russia on a United Nations resolution that it said would prevent "mass atrocities" in besieged areas of Aleppo, Syria, where thousands of trapped civilians and rebel fighters await evacuation in freezing temperatures.
On the ground, prospects for swift evacuations from Aleppo and other war-torn areas were thrown into doubt again on Sunday after militants burned buses assigned to the rescue operation, although one convoy of five buses was reported to have reached safety from the city later that night.
The Aleppo evacuations were to have been part of a wider deal that would simultaneously allow more than 2,000 sick and wounded people to leave two pro-government villages that have been besieged by Syrian rebels. Most villagers are Shiite Muslims, while most rebels are Sunni Muslims.
Six buses that were among those poised to enter the villages of Foua and Kfarya on Sunday were set on fire by unidentified militants, presumably to scuttle any deal.
A video posted online showed armed men near the burning buses as celebratory gunshots rang out. "The buses that came to evacuate the apostates have been burned," the narrator of the video said. He warned that no "Shiite pigs" would be allowed to leave the towns.
Earlier on Sunday, pro-Syrian government TV stations showed dozens of buses on stand-by at a crossing near eastern Aleppo, reportedly poised to resume evacuations from the opposition's last foothold in the city.
Later, a Syrian opposition war monitoring group said the first civilians and fighters to evacuate eastern Aleppo in over 48 hours arrived safely in the countryside from the city. The British-based Syrian Observatory for Human Rights said shortly before midnight Sunday that government forces allowed five buses to leave Aleppo.
Evacuations were suspended two days earlier amid mutual recriminations after several thousand people had been ferried out of the war zone. Thousands more desperate civilians are believed to be trapped in the city.
About 2,700 children were evacuated in the first rescue mission earlier this week, but hundreds more "are now waiting in freezing temperatures, close to the front lines", said Shushan Mebrahtu of the UN children's agency Unicef. "We are deeply worried."
The troubled evacuations are throwing into disarray an Aleppo deal that was brokered last week by Syria ally Russia and opposition supporter Turkey.
The deal marked a turning point in the country's civil war. With the opposition leaving Aleppo, Syrian president Bashar Assad has effectively reasserted his control over Syria's five largest cities and its Mediterranean coast nearly six years after a national movement to unseat him took hold.
At the United Nations, France and Russia announced agreement on a compromise UN resolution to deploy UN monitors to eastern Aleppo to ensure safe evacuations and immediate delivery of humanitarian aid.
France's UN ambassador Francois Delattre told reporters the compromise was reached after more than three hours of closed consultations on Sunday and the Security Council would vote on the resolution at 9am New York time on Monday.
He said some countries wanted to report to their capitals overnight and he hoped for a positive vote, but remained cautious.
Russia's UN ambassador Vitaly Churkin told reporters before consultations that Moscow could not accept the French draft resolution unless it was changed and presented council members with a rival text.
After the consultations, Mr Churkin said a "good text" had been formulated.
US ambassador to the UN Samantha Power said the resolution would quickly put more than 100 UN staff on the ground to monitor evacuations.
"The text contains all the elements for safe, secure, dignified evacuation, for humanitarian access to those who choose to remain in eastern Aleppo" and for protecting civilians, she said.
She said that following the siege in eastern Aleppo, there have been "many, many reports of people being pulled off buses and disappeared, whether into conscription or into torture chambers or killed outright". Deploying UN monitors would deter "some of the worst excesses", she said.
Mr Delattre agreed, saying approval of the resolution "would give us collectively the tools to avoid a situation in which, after the end of major military operations, forces including militias, would commit mass atrocities".
He said the resolution could also offer leverage to negotiate a broader ceasefire.