A 42-year-old Russian man literally ran for his life for seven kilometers in the freezing cold after he accidentally fell off a train in the country's Far East - wearing only a T-shirt, sweatpants and slippers.

­The man said that he had gone to the train's vestibule for a smoke. As he was coming back to his carriage, he missed his door and opened another one to a non-functioning vestibule. He stepped into the dark - and then found himself in taiga forest, on the railroad, all alone.

The passenger ran after the train for seven kilometers, but couldn't catch up with it. At the next station - 'Richard Sorge,' only 150 kilometers away from the train's final destination - the man was given help.

"The 42-year-old man survived by sheer luck," the Interior Ministry's local transport department reported on Friday.

An investigation into the matter has been launched, and police are trying to ascertain whether what happened was an accident, or whether a train attendant forgot to close the door out of neglect.

Local media reported that the man turned out to be a driver working under a rotation system in Russia's Far East. "He is feeling fine, has already started working, and has suffered no bodily harm. Certainly, he had been very scared, but got over the shock," the man's employer told Komsomolskaya Pravda newspaper.

The train was traveling from Moscow to Nerungri, a city in Russia's Far East, which has a population of just over 62,000 people. The average winter temperatures in the area measure around -30°C.