Reports suggest that the train collided with an excavator near the desert city of Tabas.
17 people have died after a passenger train derailed in eastern Iran, the semi-official Fars news agency has said, while over 50 passengers were seriously injured.
The number of casualties could rise, though initial details about Wednesday’s disaster involving a train reportedly carrying some 350 passengers remained unclear.
Four of the seven carriages in the train derailed in the early morning darkness near the desert city of Tabas, Iranian state television reported. Tabas is some 550km (340 miles) southeast of the capital, Tehran.
Rescue teams with ambulances and helicopters have arrived in the remote area where communication is poor. At least 16 people suffered critical injuries, with some transferred to local hospitals, officials said.
The derailment happened some 50km (30 miles) outside of Tabas on the rail line that links the city to the central city of Yazd. Photos from the scene, published by the Young Journalists Club associated with state TV, appeared to show train carriages on their side as rescuers tried to care for the injured.
Initial reports suggested the train collided with an excavator near the track, though it was not immediately clear why an excavator would have been close to the train track at night. One official suggested it could have been part of a repair project.
Iran’s worst train disaster came in 2004 when a runaway train loaded with petrol, fertiliser, sulphur and cotton crashed near the historic city of Neyshabur, killing some 320 people, injuring 460 others and damaging five villages. Another train crash in 2016 killed dozens.
Iran has some 14,000km (8,700 miles) of railway lines throughout a country about two and a half times the size of Texas. Its rail system sends both people and goods across the country, particularly in rural areas.
Iran also has some 17,000 annual deaths on its highways, one of the world’s worst traffic safety records. The high toll is blamed on a wide disregard for traffic laws, unsafe vehicles and inadequate emergency services.
Iran, already straining under United States sanctions over its collapsed nuclear deal, has been mourning the deaths of at least 41 people killed in a building collapse in the country’s southwest.