Syrian warplanes have killed more than 300 people, including 87 children, in an eight-day bombing campaign against rebel-held parts of the northern city of Aleppo, a monitor said Monday.

"From December 15 to 22, 301 people have been killed, including 87 children, 30 women and 30 rebels," said the Syrian Observatory for Human Rights, which relies on a network of activists and witnesses on the ground to track the civil war.