Fifty-seven people were killed on Thursday in Syrian air force raids against areas controlled by Syrian rebels, according to the London-based Syrian Human Rights Observatory.

The strikes were in retaliation for shells fired by the rebels against residential neighborhoods in Damascus and took place in rebel-held areas east of the city.

The list of casualties include 12 children and seven women, according to the NGO, whereas 140 people were injured.

Residents in the areas under attack sought refuge in buildings’ basements, according to an AFP reporter.