Russia says Syria's army has halted its attacks in Aleppo to allow trapped civilians to be evacuated.
Foreign Minister Sergei Lavrov says around 8,000 people would be taken out of the besieged city.
Government forces have retaken three quarters of east Aleppo in recent weeks - areas rebels have controlled for four years.
However, residents and fighters are reporting no let-up in the bombing and shelling campaign.
"Battles are intense," said a message from a rebel operation room shared with The Associated Press.
Other residents reported warplanes firing from machine guns at rebel positions and artillery shells falling in the remaining rebel-controlled districts.
Medical officials in the enclave issued a passionate plea for a ceasefire.
"Aleppo is finished. There is nothing left except a few residents and bricks," Mohammed Abu Jaafar, the head of the eastern Aleppo forensic authority, said in a recorded message shared with reporters. "This may be my last call."
By early afternoon, Mr Abu Jaafar said 14 bodies had arrived at his facility from all over eastern Aleppo, although a comprehensive death toll for the day was not possible because of the intense fighting.
Residents described streets littered with bodies as ambulances and rescue workers struggled to keep up.