Air raids on Friday killed at least 11 civilians in a region of eastern Syria controlled by the jihadist Islamic State group, the Syrian Observatory for Human Rights reported.

"At least 11 civilians -- among them four women and four children -- were killed in Syrian or Russian air raids on the Al-Boulil region that is controlled by the Islamic State group in the eastern province of Deir Ezzor," the Britain-based monitor said.

The area is some 30 kilometres (18 miles) southeast of the provincial capital Deir Ezzor city, which has been largely under IS control since 2013.

Syria's state news agency SANA reported that government aircraft destroyed "two sites containing weapons and military equipment of the Daesh (IS) terrorists" southeast of Deir Ezzor.

IS has been trying to take the entire province, where part of the capital and the military airport are still under the control of government forces.

On Thursday, the jihadist group said it had shot down a regime MiG warplane south of the provincial capital, killing its pilot.

It said the jet had attacked several villages before being targeted and crashing.

The Observatory -- which relies on a network of sources inside Syria for its information -- said the plane downed on Thursday was the fourth shot down by IS since April.