ISTANBUL -- The buses waiting in Aleppo Wednesday morning were supposed to evacuate fighters and civilians from the last remaining rebel-held section of the city.

Instead, the cease-fire collapsed -- there was shelling and more airstrikes -- and the buses went away empty.

Several thousand civilians -- men, women and children -- are holed up in around two square miles of territory with Aleppo now nearly entirely under the Syrian regime’s control.

Syrian rebels said Wednesday night that a new ceasefire deal was in the works, and evacuation efforts are back on.

The United Nations human rights chief said Wednesday that the bombardment of is almost certainly a violation of international law, and it may be a war crime.

The recapture of Aleppo is a major victory for the regime, after four years of fighting, but it was won by indiscriminately killing civilians with help from Syria’s allies, Iran and Russia.

Syrian President Bashar Al Assad calls the rebels “terrorists,” and in an interview Tuesday with Russian TV, he castigated the West for trying to protect them.

“It does not matter what they ask. The translation of their statement is for Russia: ‘Please, stop the advancement of the Syrian Army against the terrorists,’” Assad said.

The U.S. has condemned the regime and its friends in Russia and Iran. But in five years of civil war, America has avoided a direct confrontation with the Syrian regime, fearing a dangerous escalation and perhaps conflict with Russia.

The price of that policy has been paid by Syrian civilians with their lives.