Over 40 people have been killed in northern and eastern Syrian cities of Raqqa and Deir el-Zour in air campaign against the Islamic State group over the past 24 hours, Britain-based Syrian Observatory for Human Rights said Saturday. The report comes almost a week after the monitor said last Sunday that ISIS killed at least 135 people and abducted 400 civilians during a daylong assault in Deir el-Zour.

According to the U.K.-based monitoring group, 30 civilians were killed in airstrikes in Deir el-Zour, including 13 children and eight women. The observatory added that the death toll is expected to increase because some of those injured were in critical condition.

In Raqqa city, the de facto capital of the ISIS in Syria, 27 people — all civilians — were killed by aerial bombardment. The deceased included nine children and seven women and the number of deaths is likely to rise, the group said.

Last Sunday, ISIS killed at least 85 civilians and 50 pro-government forces. The deaths took place in Al-Baghaliyeh neighborhood, located in parts of Deir el-Zour, according to the monitor.

“The legal and moral responsibility for this barbaric and cowardly massacre committed by ISIS hordes lies on the shoulders of all the states that support terrorism and that fund and arm takfiri [Sunni extremist] organizations,” Syria’s state news agency SANA quoted Prime Minister Wael Nader al-Halqi as saying at the time.