Forty-two others were injured in the accident, which occurred in Qorveh county at 20:40 local time on Monday, reports Xinhua, quoting the semi-official Tasnim news agency.

There were 46 passengers on the bus when the accident occurred in Qorveh county at 20:40 local time, Hossein Jafari, head of the emergency medical services of Kurdistan University of Medical Sciences, was quoted as saying.

The injured have been rushed to medical centres in the province, he added.

The official news agency IRNA said that slippery roads and over-speeding might be factors behind the accident.