A civil defence official in Aleppo says at least 53 civilians died on Tuesday in shelling by Assad's forces.
53 civilians were killed when regime forces targeted rebel-held parts of the northwestern Syrian city of Aleppo on Tuesday, according to civil defence official Necip Ensari. He said 200 other civilians were injured in the attacks.
Renewed attacks by Assad's forces that began in mid-November have so far killed 828 civilians in eastern Aleppo, the biggest city in Syria before the start of the civil war in 2011, according to civil defence officials.
Earlier, Syrian regime forces took full control of five new districts in rebel-held eastern Aleppo as they intensified their large-scale offensive to retake the city.
Regime forces entered rebel-held parts of the Old City late on Tuesday, the British-based Syrian Observatory for Human Rights (SOHR) monitoring group reported.
Pro-Assad forces have taken control of the entirety of Old Aleppo, according to @syriahr.— Louisa Loveluck (@leloveluck) December 7, 2016
A rebel official denied the report but said the army and its allies were trying to enter and that battles continue.
Assad's forces now control 70 percent of the rebels' former stronghold, according to SOHR.
The regime's gains, which include the strategic Shaar neighbourhood, have left rebels scrambling to defend the shrinking enclave they still control in Aleppo's southeastern districts.
Meanwhile, Russian Foreign Minister Sergei Lavrov said talks with the United States on a rebel withdrawal would begin in Geneva as soon as Tuesday evening or Wednesday morning.
However, sources familiar with the plans later said no talks would take place this week in the Swiss city.
TRT World's Nafisa Latic gives more details.