By Laila Bassam and Orhan Coskun

ALEPPO, Syria/ANKARA (Reuters) - Thousands of people fled the front lines of fighting inAleppo on Tuesday as the Syrian military advanced on the final pocket of rebel resistance, and a senior Turkish official said Russia and Turkey would meet to try to set up an evacuation corridor.

The rout of rebels from more than half of their ever-shrinking territory in Aleppo sparked a mass flight of civilians and insurgents 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 rebel-held area as “a hellish corner” of less than a square kilometer, 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 told Reuters, 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 rebel area of Aleppo said rebels 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 rebels in Aleppo would mean the end of the rebellion 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, Syrian President Bashar al-Assad’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 rebels, including groups backed by the United States, Turkey and Gulf monarchies, as well as jihadist groups that the West does not support, will suffer a crushing defeat in Aleppo, the war will be far from over.

STRINGER via Getty Images

”FLEEING IN PANIC”

Aleppo’s loss will leave the rebels 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.

Islamic State 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 rebels during their retreat in the city, a Syrian military source said on Tuesday.

After days of intense bombardment of rebel-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 rebel-held areas, the Syrian Observatory for Human Rights, a British-based war monitor, reported. Rebels 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 rebels,” said Abu Ibrahim, a resident of Aleppo in a text message.

Colville said he feared retribution. “In all, as of yesterday evening we have received reports of pro-government forces killing least 82 civilians, including 11 women and 13 children, in four different neighborhoods - 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 insurgent group in Aleppo said on Monday night that they had established a new frontline along the river.

Celebrations on the government side of the divided city lasted into Monday night, with fighters shooting rounds into the sky in triumph.

Abdalrhman Ismail / Reuters Children push containers in strollers as they flee deeper into the remaining rebel-held areas of Aleppo, Syria December 12, 2016.

TIDE OF REFUGEES

A daily bulletin issued by the Russian Defence Ministry’s “reconciliation center” 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.

State 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 rebel 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.

(Reporting By Laila Bassam in Aleppo, Orhan Coskun in Ankara, Lisa Barrington and Tom Perry in Beirut, Suleiman al-Khalidi in Amman and Stephanie Nebehay in Geneva; Writing by Angus McDowall in Beirut; Editing by Pravin Char and Peter Millership)

Abdalrhman Ismail / Reuters A man pushes a cart carrying an elderly woman and belongings as they flee deeper into the remaining rebel-held areas of Aleppo, Syria December 12, 2016.

FIGHTING

The Syrian army is backed by Russian war planes and Lebanese and Iraqi Shi’ite militias supported by Iran. Its advances on Monday were aided by a militia of Palestinian refugees in Syria, the Liwa al-Quds or Jerusalem Brigade, the general said.

The mostly Sunni rebels include groups backed by the United States, Turkey and Gulf monarchies as well as hardline jihadists who are not supported by the West.

A correspondent for Syria’s official SANA news agency said the army had taken control of Sheikh Saeed, and more than 3,500 people had left at dawn.

A Syrian official told Reuters: “We managed to take full control of the Sheikh Saeed district. This area is very important because it facilitates access to al-Amariya and allows us to secure a greater part of the Aleppo-Ramousah road.” The road is the main entry point to the city from the south.

Riad Hijab, Syria’s chief opposition coordinator, said the rebels’ defeat in Aleppo would not weaken the resolve of Assad’s opponents, or push them to water down the demand that he quit.

“If Assad and his allies think that a military advance in certain quarters of Aleppo will signify that we make concessions, then (I say) that will not happen,” he told reporters after meeting French President Francois Hollande.

The loss of Palmyra, an ancient desert city whose recapture from Islamic State in March was heralded by Damascus and Moscow as vindicating Russia’s entry into the war, is an embarrassing setback to Assad.

The Observatory reported that the jihadist group carried out eight executions of Syrian soldiers and allied militiamen in Palmyra on Monday while warplanes bombarded their positions around the city.

Still, Islamic State made further advances around Palmyra, it and the Observatory said on Monday, including coming close to a military air base.

Another four people, including two children, were shot dead while the jihadists cleared the city, the Observatory said.

It said at least 34 people had died in air raids on an Islamic State-held village north of Palmyra, and that local officials said poison gas had been used. Islamic State accused Russia of the attack. Both Russia and Syria’s military deny using chemical weapons.

Omar Sanadiki / Reuters Smoke rises as seen from a government-held area of Aleppo, Syria December 12, 2016.

CIVILIANS

The Russian Defence Ministry said on Monday that 728 rebels had laid down their weapons over the previous 24 hours and relocated to western Aleppo. It said 13,346 civilians left rebel-controlled districts of Aleppo over the same period.

“Displaced people are moving,” said an Aleppo resident. Some were moving from areas controlled by the army to opposition areas, while others were going in the opposite direction. Some were staying at home waiting for the army.

The Observatory said that four weeks into the army offensive at least 415 civilians, including 47 children, had been killed in rebel-held parts of the city.

The Observatory said 364 rebel fighters had been killed in the eastern sector. It said rebel shelling of government-held west Aleppo had killed 130 civilians including 40 children.