Syrian government artillery fire killed 21 civilians, including two children, in an eastern district of Aleppo early Wednesday, a monitoring group said.
The Syrian Observatory for Human Rights said at least eight of those killed were civilians who had fled from elsewhere in the east as a government forces advance and sought refuge in rebel-held Jubb al-Qubbeh.
The Britain-based monitor said dozens more were wounded in the “fierce” shelling, and many people were stuck under the rubble of collapsed buildings.
Tens of thousands of people have poured out of the rebel-held northeast in recent days, with some crossing into territory held by either the government or Kurdish forces, but others moving south into remaining rebel-held territory.
The White Helmets rescue group published photos of the aftermath of the attacks, showing an apocalyptic scene with bodies and parts of flesh strewn on a street among the rubble of surrounding buildings.
In one image, a young man appeared to weep next to two bodies, their top halves obscured by blankets.
The feet of one body were clad in pink socks, the other wore red boots done up with white laces.
Suitcases and plastic bags were strewn among the bodies, which the White Helmet workers carefully transferred into orange body bags.
Some of the displaced have been sleeping in streets after arriving in remaining rebel-held territory, with others seeking refuge in abandoned buildings left behind by earlier waves of fleeing residents.
East Aleppo has seen some of the worst violence of the conflict that began in March 2011 with anti-government protests before spiralling into a civil war after a regime crackdown.
The government announced in September that it planned to retake all of the city, and on November 15 launched a new operation, pounding the east with air strikes, barrel bomb attacks and artillery fire.
The operation has killed nearly 300 civilians in east Aleppo, including more than 30 children, the Observatory has said.
Rebels have also fired rockets into western Aleppo, killing nearly 50 people since the latest assault began, according to the monitor.
Syrian state news agency SANA on Wednesday said that eight civilians including two children had been killed in rebel rocket fire on the west of the city.
Another seven people were wounded, the agency said, citing a police source in Aleppo.
Government forces now hold at least a third of eastern Aleppo and are pressing ahead with an assault that could deal rebels their worst blow since the conflict began.
More than 300,000 people have been killed and millions forced to flee their homes since Syria s conflict erupted in March 2011 with protests calling for Assad s ouster.