Twenty-six people were killed and 18 injured when their bus overturned some 220 kilometres (138 miles) west of Tehran, Iranian state television quoted police as saying Saturday. The accident occurred around 5:15 am (0045 GMT) and the cause of the accident was attributed to the driver's exhaustion. The passengers were on their way from the north-western town of Khoy to the north-eastern city of Mashhad.
Iran's roads are considered to be among the most dangerous in the world, with some 100,000 road-accident deaths in the past five years.
On June 24, about 90 people died near south-eastern Zahedan when a fuel truck lost control and crashed into a police station, with the explosion engulfing other trucks, cars and buses.