Damascus, May 26 (RHC)-- At least 35 people have been were killed by U.S.-led airstrikes on areas in eastern Syria, a monitor group reported. 

The airstrikes targeted areas under the control of the Islamic State (IS) group in the city of Mayadeen in the countryside of Deir al-Zour province, said the Syrian Observatory for Human Rights. 

A day earlier, the Observatory said that 16 civilians were killed by U.S.-led strikes on the northern city of Raqqa, the de facto capital of the Islamic State, just hours after 15 civilians were killed as a result of mine explosions in Raqqs countryside. 

Raqqa and Deir al-Zour have been the target of the U.S.-led coalition, which is backing the Kurdish-led Syrian Democratic Forces (SDF) in their push against IS in Raqqa countryside and areas near Deir al-Zour. 

As a result, civilian casualties have been rising recently with reports of civilian deaths due to the intensification of U.S.-led strikes.