Thousands of people fled the front lines of fighting in Aleppo on Tuesday as the regime advanced on the final pocket of opposition resistance, and a senior Turkish official said Russia and Turkey would meet to try to set up an evacuation corridor.
The rout of opponents from more than half of their ever-shrinking territory in Aleppo sparked a mass flight of civilians and opposition fighters in bitter weather, a crisis the United Nations said was a "complete meltdown of humanity".
The U.N. human rights office said it had reports of abuses, including that the army and allied Iraqi militiamen summarily killed at least 82 civilians in captured city districts.
"The reports we had are of people being shot in the street trying to flee and shot in their homes," said Rupert Colville, spokesman for the U.N. office. "There could be many more."
Behind those fleeing was a wasteland of flattened buildings, concrete rubble and bullet-pocked walls, where tens of thousands had lived until recent days under intense bombardment even after medical and rescue services had collapsed.
Colville described the opposition-held area as "a hellish corner" of less than a square kilometre, saying its capture was imminent.
Turkish and Russian officials will meet on Wednesday to discuss a possible ceasefire and the opening of a corridor, the Turkish official said, who declined to be identified.
But international efforts to seek a negotiated settlement to end fighting in Aleppo have shown no signs of a breakthrough, with Russia and the United States exchanging recriminations over hitches in ceasefire talks.
The spokesman for the civil defence force in the former opposition area of Aleppo said opponents now controlled an area of less than three sq km. "The situation is very, very bad. The civil defence has stopped operating in the city," he told Reuters.
A surrender or withdrawal of the opposition fighters in Aleppo would mean the end of the opposition's existence in the city, Syria's largest until the outbreak of war after mass protests in 2011, but it is unclear if such a deal can be struck by world powers.
By finally dousing the last embers of resistance burning in Aleppo, the regime's military coalition of the army, Russian air power and Iran-backed militias will have delivered him his biggest battlefield victory of the war.
However, while the opponents, including groups backed by the United States, Turkey and Gulf monarchies will suffer a crushing defeat in Aleppo, the war will be far from over.
Aleppo's loss will leave the dissidents without a significant presence in any of Syria's main cities, but they still hold much of the countryside west of Aleppo and the province of Idlib, also in northwest Syria.
Daesh also has a big presence in Syria and has advanced in recent days, taking the desert city of Palmyra.
The army and its allies had taken full control over all the Aleppo districts abandoned by dissidents during their retreat in the city, an Assad's military source said on Tuesday.
After days of intense bombardment of opposition-held areas, the rate of shelling and air strikes dropped considerably late on Monday and through the night as the weather deteriorated, a Reuters reporter in the city said.
However, rocket fire pounded opposition-held areas, the Syrian Observatory for Human Rights, a British-based war monitor, reported. dissidents and government forces still fought at points around the reduced enclave, the Observatory said.
"Artillery shelling is continuing but because of the weather the aerial bombing has stopped. Many of the families and children have not left for areas under the control of the regime because their fathers are from the opponents," said Abu Ibrahim, a resident of Aleppo in a text message.
Colville said he feared retribution and massacre. "In all, as of yesterday evening we have received reports of pro-Assad forces killing least 82 civilians, including 11 women and 13 children, in four different neighbourhoods - Bustan al-Qasr, al-Fardous, Al-Kalasah and al-Saliheen," Colville told a news briefing, naming the Iraqi armed group Harakat al-Nujaba as reportedly involved in the killings.
The military official said the rebels were fleeing "in a state of panic", but a Turkish-based official with the Jabha Shamiya opposition group in Aleppo said on Monday night that they had established a new frontline along the river.
A daily bulletin issued by the Russian Defence Ministry's "reconciliation centre" from the Hmeimin airbase used by its warplanes, reported that more than 8,000 civilians, more than half of them children, had left east Aleppo in 24 hours.
Regime's television broadcast footage of a tide of hundreds of refugees walking along a ravaged street, wearing thick clothes against the rain and cold, many with hoods or hats pulled tight around their faces, and hauling sacks or bags of belongings.
One man pushed a bicycle loaded with bags, another family pulled a cart on which sat an elderly woman. Another man carried on his back a small girl wearing a pink hat.
At the same time, a correspondent from a pro-Damascus television station spoke to camera from a part of Aleppo held by the government, standing in a tidy street with flowing traffic.
Abu Malek al-Shamali, a resident in the opponent area, said dead bodies lay in the streets. "There are many corpses in Fardous and Bustan al Qasr with no one to bury them," he said.
"Last night people slept in the streets and in buildings where every flat has several families crowded in," he added.
The International Committee for the Red Cross appealed for all sides to spare civilian lives. "As the battle reaches new peaks and the area is plunged into chaos thousands with no part in the violence have literally nowhere safe to run," it said.
