At least 30 people were killed in air strikes in Syria's eastern Deir Ezzor province and many were injured.At least 50 people had died and "many" had been injured in the air raids on the outskirts of the provincial capital Deir Ezzor on Wednesday.The identity of the war planes that carried out the bombardments was not known, the reports said.On Tuesday at least 57 people died in an aerial attack on a prison run by the Islamic State jihadist group in the Deir Ezzor city of Mayadeen, the Syrian Observatory for Human Rights monitoring group reported.Those killed included 42 prisoners and 15 IS militants, the British war monitor said, adding that "in all probability" the air raids were carried out by the US-led international coalition against IS.The coalition has been accused repeatedly this year of causing civilian casualties as it targets IS's rapidly shrinking territory in both Syria and Iraq, but US military officials say higher civilian casualties were always expected as the IS militants are increasingly squeezed into shrinking territory.