The accident occurred late Friday night 30 kilometers (18.5 miles) from Golpayegan on the road to Isfahan.
The accident is said to have happened in fog when one of the buses moved to the left on the narrow road.
Iran’s roads are considered to be among the most dangerous in the world, with some 100,000 road-accident deaths in the last five years.
On June 24, about 90 people died in southern Sistan-Baluchestan province when a fuel truck lost control and crashed into a police station, with the explosion engulfing other trucks, cars and busses.
More than a quarter of all Iranian cars are over 20 years old, and drivers in general seem to display near-suicidal tendencies when they are behind the wheel.
