The injured have been discharged from the hospital after being treated, Hirash Rezaei, director general of Kordestan Province governorate general's public relations, told the Islamic Republic News Agency (IRNA).
Sanandaj police officer, Colonel Ramezan Naderi said the passenger bus had stopped out of bus terminal when the crash happened.
Experts are examining the cause of the accident, he added.
Four of the wounded were passengers of the bus and three were people in passing vehicles.
Sanandaj, the capital of Kordestan Province, is located in western Iran.
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