HELSINKI (AFP) - A passenger train smashed through a buffer stop and into a hotel in Helsinki's main station Monday after an apparent brake malfunction.

No one was badly hurt in the incident, caused when four double-deck carriages became detached from an inter-city train during reversing, communications director Hanna von Wendt said.

The reasons for the accident were "not quite known," she said, adding that one of the three railway employees aboard "sustained minor injuries."

After smashing through the buffers the runaway carriages slammed into the hotel building's third floor.

The hotel was evacuated and eight train platforms were shut, causing serious delays to services.