Air raids killed 19 civilians, including three children, in rebel-held districts of Syria's battleground second city Aleppo on Tuesday, a monitoring group said.

Rebel fire meanwhile killed five people in a government-held western district, according to Syrian state television.

The Syrian Observatory for Human Rights said dozens were wounded, some of them critically, in the strikes on the rebel districts of Tariq al-Bab and Al-Sakhur neighbourhoods carried out by either Russian or regime aircraft.

An AFP journalist in east Aleppo said there were heavy air raids throughout Monday night and into the day on Tuesday in both districts.

Men were seen pulling debris and rubble from the ground floor of a building, while others zipped corpses into black body bags.

A dust-covered van with the windows blown out -- with the word "Ambulance" on its dented side -- slowly pulled away from the scene of the attack.

Since mid-2012, Aleppo has been divided between opposition control in the east and government forces in the west, with both sides exchanging accusations of indiscriminate attacks against civilians.

The Britain-based Observatory said that 12 rebels were also killed in Russian air strikes Tuesday targeting a convoy of anti-regime fighters on the city's southern outskirts.

The monitoring group's head, Rami Abdel Rahman, said the convoy was travelling into Aleppo via the Ramussa road, the access route rebels opened in early August into parts of the city they control.

That road has been used to bring vegetables, petrol and other goods into eastern Aleppo, marking the end of a three-week government siege of those districts. 

Rebels, Islamists and jihadists are locked in clashes with regime forces on the southern edges of Aleppo in a bid to keep the route open. 

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.

More than 290,000 people have been killed since Syria's conflict erupted in March 2011 with anti-government protests that escalated into a brutal multi-front war. 

Source: AFP