Syrian government forces are poised for the final sweep to take the last rebel holdouts in eastern Aleppo today.
Meanwhile, the international community and aid agencies are appealing for the lives of thousands of civilians who have "nowhere safe to run" to be spared and that those fighting to capture the rebel enclave refrain from atrocities.
The dramatic appeals came a day after the Syrian military announced it now holds 99% of the former rebel neighbourhoods of Aleppo, signalling an impending end to the rebels’ four-year hold over parts of the city as the final hours of the battle play out.
Retaking Aleppo, which has been divided between rebel- and government-controlled zones since 2012, would be President Bashar Assad’s biggest victory yet in the country’s civil war. Aleppo has long been regarded as a major gateway between Turkey and Syria.
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.
The International Committee of the Red Cross issued a statement on Tuesday, urging all fighting in Aleppo to spare civilian lives. It said thousands of people 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 the ICRC’s head of delegation in Syria, Marianne Gasser, who is currently in Aleppo. "We stand ready to oversee the implementation of any mutual agreement that puts civilians first. We cannot urge this strongly enough: this must happen."
UN Secretary-General Ban Ki-moon said in a statement late on Monday that he is alarmed over reports of atrocities against a large number of civilians, including women and children, in the past hours in Aleppo. While stressing that the United Nations is not able to independently verify these reports, the UN chief said he conveyed his grave concern to the relevant parties.
Mr Ban also said the UN underlines the obligation of all parties on the ground to protect civilians and abide by international humanitarian and human rights law, adding that "this is particularly the responsibility of the Syrian government and its allies".
In Moscow, which has been Assad’s major ally in the war, the Defence Ministry said on Tuesday that Syrian forces now control "more than 98%" of Aleppo and the rebels are holding out a neighbourhood roughly the size of 1.2 square miles.
Several Syrian opposition activists claimed government forces were carrying out summary killings of rebels in the streets in neighbourhoods captured on Monday but the Syrian military denied the claims, saying such allegations were "a desperate attempt" to try to gain international sympathy.
Turkey’s Deputy Prime Minister, Numan Kurtulmus, called for an immediate ceasefire and if that is too late, he called on the international community, European countries, regional countries and Turkey to organise an international aid convoy to people in need in Aleppo.
On Monday, members of staff at the last remaining clinic in rebel-held territory in Aleppo huddled in a shelter as Syrian government forces pushed in.
"Those killed and wounded are left on the streets," said the clinic’s administrator, Mohammed Abu Rajab.
"The collapse is terrifying," said Bassam Haj Mustafa, a rebel spokesman in contact with fighters in the city. Opposition fighters were "doing their best to defend what is left", he added.
Rami Abdurrahman, who heads the Britain-based Syrian Observatory for Human Rights, said more than 60 civilians and fighters were killed in rebel-held neighbourhoods of Aleppo on Monday alone.