The crash occurred at Haft-Khan station, on the railroad linking the cities of Semnan and Damghan, in a mountainous area at around 8 a.m. local time.
A passenger train travelling between capital Tehran and the northeastern holy city of Mashhad was stopping at the station when another train hit it from behind.
The crash, which has burnt a number of cars, has killed at least 5 people and wounded 11 others, according to provincial head of the Red Crescent Society, Shokrollahi.
Rescue teams and helicopters have been dispatched to the site of accident, he added.
