Air strikes killed at least 12 civilians including children in two rebel-held neighbourhoods of Syria's Aleppo city on Thursday, a monitoring group said.

Nine people were killed in the Tariq al-Bab neighbourhood, and another three in the district of Salhin in the east of the city, the Syrian Observatory for Human Rights reported.

The Britain-based group said it was unclear whether the strikes were carried out by warplanes of the Syrian government or its ally Russia.

(AFP)