At least 30 civilians were killed in air strikes on an area of eastern Syria held by the Islamic State group on Wednesday, a monitoring group said.

The Syrian Observatory for Human Rights said it was not immediately able to say whether the strikes in Deir Ezzor province were carried out by the US-led coalition, or by the Syrian army or its Russian ally.

They came just two days after a suspected coalition strike on an IS jail in the province killed 42 prisoners and 15 jihadists, according to an Observatory toll.