Every hour, butcheries are carried out.
Syrian government forces are close to taking total control of Aleppo from rebels, and civilians are reportedly facing mass executions.
The United Nations said Tuesday that it had received reports of 82 civilians being shot on sight on Monday. Many were killed in their homes, CNN reports.
The U.N. was unable to confirm the casualty reports, but Secretary-General Ban Ki-moon expressed his concern in a statement.
Only one Aleppo neighborhood is still held by rebel forces, and that last holdout seems doomed to fall soon, after four years of fighting with forces loyal to Syrian President Bashar al-Assad.
Humanitarian groups have pleaded for a safe passage for about 100,000 civilians trapped in the eastern half of Aleppo, once the most-populated city in Syria and the nation's commercial hub.
We can't believe the world's most powerful countries can't get 100.000 civilians to safety that is 4 KM away! #SaveAleppo pic.twitter.com/RAvyRHJeO0
— The White Helmets (@SyriaCivilDef) December 13, 2016
The White Helmets volunteer rescue group condemned the lack of international intervention.
There is no total number of casualties in Besieged #Aleppo today, all streets & destroyed buildings are full with dead bodies. It's hell.
— The White Helmets (@SyriaCivilDef) December 13, 2016
The situation in the city is still nightmarish.
WATCH | Here's a look at the government forces attempting to retake the city.
These photos show displaced civilians and troops in Aleppo, courtesy of the International Committee for the Red Cross.
this is a call and might be the last call.
— @Mr.Alhamdo (@Mr_Alhamdo) December 12, 2016
Save Aleppo people. Save my daughter and other children. #StandWithAleppo
Many residents have posted what are believed to be their last words on Twitter.
We're deeply frustrated, but we're not surprised by this lack of Russian and regime commitment to what should be a humane solution.
The United States and Russia have attempted to establish a ceasefire in the region, but have been unable to come to an agreement. On Sunday, they appeared close, but U.S. State Department spokesman John Kirby said the Russians imposed unacceptable delays and the deal fell through.