(CNN) At least 26 people have been killed, including six children, in airstrikes from Monday, which have targeted rebel-held areas of the northern Syrian city of Aleppo, according to the UK-based monitoring group Syrian Observatory for Human Rights (SOHR). Nine other people were wounded, some in critical condition, SOHR said. CNN has not been able to independently verify such claims. It wasn't clear who conducted the airstrikes, but the opposition and the US have blamed the Syrian regime and Russian warplanes for such attacks since a ceasefire broke down. SOHR claimed rebel-held areas in the eastern part of the city had been struck by barrel bombs Tuesday, as fighting between regime and rebel forces continues throughout the city. Throughout the conflict the crude explosives have been the calling card of Syrian government forces.At least 26 people killed in further airstrikes on besieged Syrian cityUN chief, US ambassador slam Assad regime's heavy bombardment of Aleppo
As _ was hammered by airstrikes, activists and aid workers posted dozens of pictures and videos online.