, Air strikes and barrel bomb attacks killed 16 civilians in rebel-held parts of Aleppo province on Monday, with rebel rocket fire onto government areas killing three more, a monitor said.
The Britain-based Syrian Observatory for Human Rights said 10 civilians had been killed in multiple air strikes on the town of rebel-held Atareb in Aleppo province.
The group said the strikes in the early hours of Monday morning were believed to have been carried out by Russian warplanes, and hit several locations including a market area.
Russia is a key ally of the government and began air strikes in support of regime forces in September 2015.
The 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.
Footage obtained by AFP of the aftermath of the strikes showed the local civil defence unit trying to put out a fire in the rubble of one collapsed building.
Nearby, people combed through the debris trying to extract medicine from what appeared to be the remains of a pharmacy or clinic.
Elsewhere, crushed fruit and vegetables were mixed in with pieces of brick and concrete.
In Aleppo city meanwhile, at least six civilians were killed in barrel bomb attacks by government forces on eastern rebel-held neighbourhoods, the Observatory said.
The monitor said the toll was expected to rise because of the number of people with injuries and still trapped under rubble.
An AFP journalist at the scene of one of the attacks in the Al-Mashhad neighbourhood said civil defence workers were struggling to retrieve survivors who were trapped under heavy pieces of debris.
He said rescuers had managed to pull one boy alive from the rubble, but the rest of his family were dead and still trapped beneath the remains of a collapsed building.
Once Syria’s economic powerhouse, Aleppo has been ravaged by the conflict that began in March 2011 with anti-government protests.
The city has been roughly divided between government control in the west and rebel control in the east since mid-2012.
In recent weeks, government forces seized parts of the only remaining supply route into the city’s east, severing opposition neighbourhoods from the outside world and prompting food shortages and spiralling prices.
The government regularly bombs the east of the city, and rebels often fire rockets into western districts.
The Observatory said at least three civilians had been killed in rebel fire on western Aleppo on Monday.
Syrian state news agency SANA said the dead were a pregnant woman and her child.
More than 280,000 people have been killed in Syria since the conflict began, and more than half the country has been displaced.