Among the fatalities on Saturday were 13 children and at least 10 combatants of the Al Nusra Front, which is linked to Al Qaeda, according to a communique issued by the independent group, which has a wide network of activists on the ground in the war-torn Middle Eastern nation.
The targets of the deadliest barrel-bomb attacks were the Tarik Bab neighbourhood, where 34 people died, and the Al Salihin and Al Marya zones, where a combined total of at least 22 people perished.
Apart from the regime's air attacks, at least 26 people died in armed clashes between rebel brigades and members of the Islamic State of Iraq and the Levant, which is also linked to Al Qaeda.
Moreover, the ISIL on Saturday carried out a car bomb attack on an insurgent military base, killing about 15.
Clashes between rebels and the forces of the Bashar al Assad regime near the Aleppo prison resulted in the deaths of nine fighters.
On the outskirts of Damascus, the Assad regime troops backed by combatants from the Shiite Lebanese group Hezbollah on Saturday fought forces from the ISIL, the Al Nusra Front and other rebel brigades in the area of Rima near the city of Yabrud, although no casualty figures were available.
Also, near Damascus, at least 13 rebel combatants died on Saturday in an ambush by regime forces in Al Guta.
At least 36 people, including 17 children and seven women, died on Sunday in aerial bombardments by the Syrian regime against neighbourhoods located in the eastern part of Aleppo, the Observatory said.
Since the Syrian conflict broke out in March 2011, some 136,000 people have died, the Observatory says, while 2.5 million people require humanitarian aid and more than 250,000 have taken refuge in neighbouring countries, according to UN figures.