At least four people were killed and 30 others were wounded as a bus overturned on an intercity road in Iran's eastern South Khorasan province on Tuesday, state-run IRIB news agency reported.
The incident occurred in Darmian County at 6:40 a.m. local time (0310 GMT), IRIB quoted the province's deputy traffic police chief as saying.
The bus was carrying 40 passengers, said the official, adding that those wounded in the incident were transferred to hospital. The cause of the incident remains under investigation.