It said five of those killed in Saturday's bombing were children.
"Warplanes bombed areas in the neighbourhoods of Tariq al-Bab and Karam al-Jabal in Aleppo," as well as the city's Sukhur district, said the Britain-based monitoring group which relies on a network of activists on the ground for its reports.
The areas are controlled by opposition fighters who have been battling forces loyal to the government of President Bashar al-Assad since they launched a major offensive in the city in the summer of 2012.
The Observatory also said "helicopters dropped explosive-packed barrels on Al-Bab town (east of Aleppo) that led to the death of several fighters from the (jihadist) Islamic State of Iraq and the Levant (ISIL), leaving an unknown number of people wounded.
Helicopters also launched raids with "barrel bombs" on other areas of the northern city, once Syria's commercial capital, and two villages in the south of Aleppo province, said the Observatory without giving further details on casualties.
In December, regime warplanes launched a series of raids with the powerful barrel bombs in Aleppo province, killing more than 500 people in nearly two weeks.
Elsewhere in the country, government jets pounded two areas east of the capital Damascus in eight raids, the Observatory reported, without saying whether there had been any casualties in the attacks.
Meanwhile, the Observatory said that clashes raged between ISIL and rival rebel groups in Aleppo province on Saturday.
Fighters from groups battling the jihadist ISIL seized a village in the province, but lost ground to the other rebels in the town of Manbaj, according to the Observatory.
Nine members of one rebel group taking part in the battle against ISIL were killed early on Saturday, the Observatory reported, when a car bomb went off at a checkpoint they were manning in rural Aleppo.