At least 17 people were killed and dozens injured Wednesday when a train derailed near the central Iranian city of Tabas after hitting an excavator beside the track, state media reported.

The train was on its way from the northeastern city of Mashhad to the central city of Yazd with 348 passengers on board when it careered off the track in the desert at 5:30 am (0100 GMT).

"Seventeen people are dead and 37 of the 86 injured people have been transferred to hospital," emergency services spokesman Mojtaba Khaledi told state television.

Map of Iran locating Tabas site of a deadly train derailment on June 8.
Map of Iran locating Tabas site of a deadly train derailment on June 8. AFP / STAFF

"The number of the dead may rise as some of the injured are in critical condition," he said, adding that "24 ambulances and three helicopters had been dispatched to the scene."

Tabas is located in South Khorasan province, roughly 900 kilometres (560 miles) by road from Tehran.

The deputy head of Iran's state-owned railways, Mir Hassan Moussavi, told the state broadcaster that the train was carrying 348 passengers.

It "derailed after hitting an excavator" that was near the track, he said.

The train was travelling between the Iranian cities of Mashhad and Yazd with 348 passengers on board when it careered off the tracks
The train was travelling between the Iranian cities of Mashhad and Yazd with 348 passengers on board when it careered off the tracks Iranian Red Crescent via AFP

Some of the injured were airlifted to hospital by helicopter, state television footage showed.

Rescue teams inspected the overturned carriages as onlookers gathered nearby, pictures posted by the ISNA news agency showed.

One of the pictures showed a yellow excavator on its side by the track.

Five of the train's 11 coaches came off the rails, the Iranian Red Crescent's head of emergency operations, Mehdi Valipour, told state television.

Iranian state media reported that the train derailed after hitting an excavator left too near the tracks
Iranian state media reported that the train derailed after hitting an excavator left too near the tracks Iranian Red Crescent via AFP

President Ebrahim Raisi expressed his grief over the derailment and offered his condolences to the families of the dead.

He also issued orders to expedite the investigation into the causes of the crash, his office said.

Roads and Urban Development Minister Rostam Ghassemi apologised to Iranians on Twitter and said the ministry was responsible for the incident.

The Tabas prosecutor visited the scene as a judicial investigation was launched, Iranian media reported.

The train derailment comes after a tower block collapsed in southwestern Iran last month killing at least 43 people.

The collapse of the 10-storey Metropol building, which was under construction in Abadan, sparked angry protests in solidarity with the families of the dead.

The provincial judiciary said it had arrested 13 people, including Abadan's mayor and two former mayors, suspected of being "responsible" for the tragedy.

The disaster was one of Iran's deadliest in years and sparked a demonstrations across the country against authorities accused of corruption and incompetence.

In 2016, two trains collided and caught fire in northern Iran, killing 44 people and injuring dozens.

The then head of Iranian railways resigned after four of his employees were arrested following the collision on the main line between Tehran and second city Mashhad.