A truck collided with a passenger bus on an open stretch of a highway between the towns of Nehbandan and Birjand.
The accident occurred at 1:30 am, the report quoted the chief of police in Nehbandan as saying.
The head of Irans traffic police Brigadier General Mohammad Rouyanian said earlier this month that the expected death toll from accidents on Irans highways for the current year stood at 31,000.
Iran’s highways are considered to be among the most dangerous in the world, with some 100,000 road-accident deaths occurring in the last five years, the equivalent of three deaths an hour.