Train communications were disrupted across the country because of sabotage carried out by the opposition activists on Tuesday.
The blockade supporters vandalised Kahalu railway station and a train in the station around 12pm, Assistant Superintendent of Police Gaziur Rahman said.
In Mymenshingh, a group of pickets removed sleepers from the railway track in the Gauripur area of the district at around 4am on Tuesday.
Five compartments of the Haor Express derailed following the removal of the sleepers from the railway tracks, leaving at least 50 people injured.
Basiruddin, officer-in-charge of Purbadhola police station, said the passengers of the train had only minor injuries.
A relief train was on its way to start the salvage work.