Activists and rescue workers say an intensive day of bombing on besieged rebel-held parts of Aleppo has left at least 25 people dead, including five children.
Rescue workers pulled at least one boy alive from under the rubble late Tuesday night.
The Britain-based Syrian Observatory for Human Rights says Tuesday's bombings killed 25 people. The Syrian Civil Defence, a team of first responders, and activist media platform Aleppo Media Centre put the death toll at 41.
Ibrahim al-Haj, of the Civil Defence, says teams are continuing to search for survivors and bodies under a collapsed building in the al-Fardous neighbourhood. He says the boy's mother is in critical condition.
Al-Haj says a bomb hit while rescuers were on the scene, injuring several of them.
The Observatory said Russian war planes had dropped so-called "bunker busters" and other bombs, with children thought to be among the dead.
The bombings have resumed on Wednesday.
