The Syrian Observatory for Human Rights said eight civilians were killed in the Bustan al-Qasr and Fardos districts in the east of the city.
"This is the heaviest Russian bombardment since the Syrian regime announced it would reduce the bombardment" on October 5, said Observatory head Rami Abdel Rahman.
An AFP correspondent in the Bustan al-Qasr district saw one multi-storey residential building that had been destroyed, its facade sheared off in the air attack.
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Members of the White Helmets rescue force pulled two lifeless toddlers from the building and wrapped them in white sheets.
The Britain-based Observatory -- which relies on a network of sources inside Syria for its information -- says it determines what planes carried out raids according to their type, location, flight patterns and the munitions involved.
Backed by Russian air raids, government forces have advanced street by street into rebel-held areas in a bid to recapture the whole of Aleppo.
At least 290 people, mostly civilians, have been killed by government or Russian fire since the operation began on September 22, the Observatory said.
On October 5, the army said it would reduce its bombardment of the east of the city and urged civilians to distance themselves from rebel fighters.