EDIT: The Aleppo ceasfire was broken early Wednesday morning.

MILITARY action has ended in eastern Aleppo, Russia’s ambassador to the United Nations has said.

Vitaly Churkin said the government had re-established control over the last areas of the city held by rebels.

The announcement brings to an end more than four years of vicious fighting.

Earlier Churkin said an arrangement had been made for rebel fighters to leave the city. Rebels have confirmed the deal.

Reporters on the ground said there had been no bombardments or fighting in recent hours.

The move came as a senior UN official warned of a “complete meltdown of humanity” in east Aleppo as President Bashar-al-Assad appeared on the point of seizing control of the city’s last remaining rebel enclave.

After a day of harrowing reports of revenge shooting of civilians and of bodies lying in the streets, Syrian rebels said an agreement had been reached with Russia for a ceasefire.

They insisted they had reached a peace deal with Moscow to evacuate residents. However, there was no comment from Damascus or Moscow and the opposition-run Syrian Observatory for Human Rights said shelling was continuing.

An agreement would effectively cede the remainder of Syria’s largest city to Assad’s forces after months of heavy fighting and a crippling siege.

Earlier aid agencies issued dramatic appeals on behalf of trapped residents and the UN human rights office said they had been told pro-government forces had killed 82 civilians “on the spot” as they closed in on remaining rebel districts.

The reports of mass killings, which could not be independently confirmed, reinforce fears of atrocities in eastern Aleppo in the final hours of the battle for the city, which has been split between rebel and government control since 2012.

Several residents and opposition activists said government forces carried out summary killings of rebels in the streets of neighbourhoods captured on Monday, but the Syrian military has denied the claims, saying they were “a desperate attempt” to try gain international sympathy.

The UN’s children agency said that there could be more than 100 unaccompanied children trapped in buildings under fire in eastern Aleppo, citing a report from an unnamed doctor in the city.

Regional director Geert Cappalaere said Unicef is concerned over the unverified reports of “extrajudicial killings of civilians, including children”.

The UN’s human rights office said it has received reports of pro-government forces killing at least 82 civilians in four neighbourhoods of the rapidly-shrinking rebel enclave, including 11 women and 13 children.

Spokesman Rupert Colville said the reports recount pro-government forces entering homes and killing civilians “on the spot”.

Jens Laerke, a spokesman for the United Nations office co-ordinating emergency relief, said 7,000 people had fled eastern Aleppo to western areas of the city and to the surrounding countryside, while some 14,700 took refuge in collective shelters. He called the events “a complete meltdown of humanity”.

UN Secretary-General Ban Ki-moon also said he is alarmed over reports of “atrocities” against a large number of civilians, including women and children.

The dramatic appeals came a day after the Syrian military announced it now holds 99 per cent of the former rebel neighbourhoods of Aleppo.

Over the last 24 hours people in the east have sent harrowing messages with their final goodbyes.

Bana Alabed, a seven-year-old girl who has been tweeting from an account managed by her mother, wrote yesterday morning: “I am talking to the world now live from East #Aleppo. This is my last moment to either live or die.”

Another, Lina Shamy tweeted: “Humans all over the world, don’t sleep! You can do something, protest now! Stop the genocide.”

Nick Finney, Save the Children’s north-west Syria country director, said: “We are desperately worried for the fate of aid workers, children and other civilians trapped in East Aleppo.

“Our partners have at least 300 humanitarian staff in the city still, living under intense bombardment with their families but fearing they will be arrested or killed if they try to leave.

“Hundreds of children are also believed to still be in the middle of this battlefield with their parents, or alone if they have been orphaned by the bombing. With no ambulances, food or medical facilities, the situation is catastrophic and has been for months.

“People’s worst fears of revenge attacks appear to have become reality – the UN says it has confirmed that 82 civilians, including 13 children, have been shot at close range and there are ‘numerous’ bodies lying in the street.”

Finney added that the warring parties are ultimately responsible for civilian deaths and suffering, but the international community, in particular the five permanent members of the Security Council, also bear a grave responsibility.

The International Committee of the Red Cross urged all parties to spare civilian lives.

It said that thousands of people in eastern Aleppo with no part in the violence “have literally nowhere safe to run”.

“In order for this to happen, we appeal to the parties to put humanity ahead of military objectives”, said ICRC’s head of delegation in Syria, Marianne Gasser, who is currently in Aleppo.

Aleppo was Syria’s largest city before the civil war and was long been regarded as a major gateway between Turkey and Syria.

It was one of the oldest continuously inhabited cities in the world and may have been inhabited since the 6th millennium BC. Before the conflict it was famed in the Middle East for its medieval architecture and traditional heritage, winning the title of the Islamic Capital of Culture 2006.

Retaking it would be Assad’s biggest victory yet in the civil war.

But a government win in Aleppo does not end the conflict – significant parts of Syria are still outside government control and huge swathes of the country are a devastated wasteland.

More than a quarter of a million people have been killed since the conflict began in 2011 with peaceful protests against the Assad family’s four-decade rule.

French President Francois Hollande pressed for Russia to facilitate humanitarian aid to civilians trapped in rebel-held parts of the city, saying the Aleppo “humanitarian situation ... is unacceptable”.

The French leader said 120,000 people were being “held hostage, there is no other word for it, who are victims of bombing, who are victims of repression” in Aleppo and that everything must be done to allow the population’s evacuation.

“Without the Russians, there is no Syrian regime that can carry out operations” on the scale of what is happening in Aleppo, Hollande added, saying that the Russians “will be responsible for a situation that they helped create if they do nothing to allow access for humanitarian aid”.

Russia said it was fed up with calls for a halt to the fighting, singling out the Obama administration, which has spent months trying to negotiate a ceasefire.

“We are tired of hearing this whining from our American colleagues in the current administration that we need to immediately halt military action,” Foreign Minister Sergey Lavrov said during a visit to Serbia.