The incident took place at around 8.30 am as a buffalo came on the railway track all of a sudden prompting the engine driver to apply emergency brake as a result of which four wheels of a sleeper bogey of the Brahmaputra Mail jumped off the track, Bhagalpur Station Superintendent Onkar Prasad said.
Some passengers sustained minor injuries after falling from their seats due to application of the emergency brake, Prasad said.
The Bhagalpur station Superintendent said Accident Relief Trains (ATRs) have been rushed from Jamalpur and Sahebput to put the detached wheels of the Brahmaputra Mail on track.
Train services on the loop section have been disrupted and another track at Lailakh Mamlakha station was being used to allow movement of passing trains.
Railway Traffic Inspector Rajiv Sharan said that no damage has been caused to Brahmaputra Mail. He said that the Railway Police Force (RPF) men have been deployed at Lailakh Mamlakha station for security of the stranded passengers.