Beirut: Syrian Army seized control of all parts of the Old City of Aleppo which had been held by rebels.
According to the Syrian Observatory for Human Rights, government troops retook seven districts including the strategic Shaar neighbourhood.
The monitor said rebels were being reduced to fighting a "war of attrition".
The latest development comes after the Army began to enter the Old City on Tuesday, part of a rapid advance which has seen rebels lose around two thirds of their besieged eastern enclave over the past two weeks.
Syria said it would not agree to any ceasefire without a guarantee of a rebel withdrawal.
Losing Aleppo would be the biggest blow yet to opposition forces in Syria`s civil war, which erupted in 2011 with protests calling for Assad`s ouster.
More than 300,000 people have since died and millions been forced from their homes.
Airstrikes on rebel-held areas in the country's northwestern city of Idlib killed 25 people on Tuesday.
The Observatory also said that five people were killed and 15 others wounded on Tuesday by rebel shelling on the Shiite towns of Kafraya and Foa in Idlib countryside.
On Sunday, at least 34 people were killed by similar airstrikes in Idlib, according to the watchdog.
Much of Idlib has fallen to the rebels over the past year, except two Shiite towns loyal to the government.
The rebels who are fleeing or evacuating areas under their control in the capital Damascus or the northern city of Aleppo were all headed toward Idlib, making the province increasingly heavy with armed militants.