Smoke rises after airstrikes on the rebel-held al-Sakhour neighborhood of Aleppo, Syria April 29, 2016. REUTERS/Abdalrhman Ismail

BEIRUT (Reuters) - At least 20 air strikes hit rebel-held areas of Syria’s northern city of Aleppo on Saturday, in the ninth straight day of violence in which bombardments by both sides have killed nearly 250 civilians, a monitoring group said.

The British-based Syrian Observatory for Human Rights did not immediately say whether Syrian government warplanes or Russian jets, which have been supporting Damascus, carried out the strikes.

Bombing by the government side on rebel-held areas of Aleppo since April 22 have killed 140 people including 19 children, the Observatory said.

Insurgent shelling of government-held areas over the same period have killed 96 people, including 21 children, it said.