Two passenger trains collided in Iran’s north-central province of Semnan on Friday, killing no fewer than 15 people and injuring dozens, Iranian media reported, saying the number of fatalities and casualties expected to rise.

"No fewer than 15 people were killed and over 20 others have been injured in the crash," it reported.

The semi-official Fars news agency said 52 people were injured, and they were transferred to nearby hospitals.

Reports gave no details on the number of passengers in the trains, but Fars said 100 passengers had been rescued.

State television showed footage of four derailed carriages, with two of them on fire.

A spokesman for Iran’s Red Crescent, Mostafa Mortazavi, told Fars that firefighters were trying to control the blaze.

“The accident happened when a passenger train in motion crashed to another one that had stopped at the station.

“The cause of the collision was under investigation,’’ it said, adding that rescue teams have been dispatched to the site of accident.

It said that they can have a better idea about number of casualties after the fire is put out.

The crash occurred at the Haft-Khan station in the city of Shahroud, about 400 kilometres east of Tehran.

A local official told newsmen that the remote location of the train station had slowed down rescue efforts.

"So far only one helicopter has reached the scene because of access difficulties," local head of the Red Crescent Hasan Shokrollahi, said.