At least 45 civilians were killed in heavy bombings of rebel strongholds east of Damascus, the Syrian Observatory for Human Rights said. Regime fforces bombed the towns of Douma, Harasta, Saqba and Arbin in the opposition-held Eastern Ghouta region, according to Agence-France Presse. One of the warplanes struck an area near a school, killing several students and the school principal. Syrian Observatory head Abdel Rahman said one rebel was killed in Sunday’s bombings.

Parts of Syria have been under heavy bombings in the last few months by anti-Islamic State forces, as well as opposing groups that are fighting in the country. This includes President Bashar al-Assad, groups that oppose his regime, the Islamic State itself and foreign powers that each have different interests. The Syrian civil war has killed more than 2,50,000 people, and driven over 10 million to flee the country.