At least 50 civilians were killed on Wednesday when Russia`s warplanes pounded the eastern Deir Ezzor province with cluster bombs, local monitoring group.
Furat Post said three Russian warplanes had carried the deadly attack on al Dablan town, topping the death toll to 115 in one week of strikes on ISIS-held areas.
On Tuesday, US-led coalition air strikes on a jail run by ISIS in eastern Syria killed at least 57 people, the Syrian Observatory for Human Rights said.
"The strikes hit an IS jail in Mayadeen at dawn on Monday, killing 44 prisoners and 15 jihadists," Observatory chief Rami Abdel Rahman told AFP.
Mayadeen lies in the Euphrates Valley some 45 kilometers (28 miles) southeast of the provincial capital of Deir Ezzor
