A pregnant woman and four children were among 15 civilians reportedly killed in a Syrian air force barrel bomb attack in the northern city of Aleppo.

Activists on Thursday said the children, who died in the strike in the residential district of Karam al-Beik in the divided city, were all less than 10 years old.

The Syrian Observatory for Human Rights confirmed the attack, adding that the crude explosives-filled container hit a building on Wednesday evening as residents were sitting down to break the daytime fast observed during the Muslim holy month of Ramadan.

The regime's bombardment always manages to suck life out of areas that are starting to rise up and recover. Abd al-Hamid al-Bakri, activist in Aleppo

An AFP news agency reporter at the scene said men were screaming as they carried the lifeless body of a boy out of the partly collapsed building before covering him with a makeshift shroud.

Rescue teams, wearing hard hats with headlamps attached, struggled to pick through the rubble in the darkness, some using just their hands to search for survivors.

Karam al-Beik has been under rebel control since 2012.

Abd al-Hamid al-Bakri, an activist in Aleppo, said that the neighbourhood had been targeted several times intermittently over the past three years, and that residents kept fleeing and coming back to their homes depending on the intensity of the violence.

"In the recent days, several families began to return to the neighbourhood because it's considered to be one of the relatively safe areas in Aleppo," he told Al Jazeera.

"But the regime's bombardment always manages to suck life out of areas that are starting to rise up and recover".

For the past three years, Syria's once economic hub has been divided between a government-held western sector and a rebel-held eastern one.

The rebels launched a major offensive in the first week of July to try to take territory on the western outskirts of the city.

More than 220,000 people have been killed in Syria since the conflict began with anti-government protests in March 2011 that were met with a bloody crackdown.

The Aleppo Media Centre, a group of opposition activists in the city, posted footage (below) of the aftermath of the attack.