A police constable fired at his senior on board a train here on Monday which they had boarded as part of the escort team, an official said.
Superintendent of Police (Railway), Katihar, Dilip Kumar Mishra said the incident took place near while the Sealdah-bound "Hate Bazare Express" was approaching Karhagola Road station in the district.
The constable, Dayanidhi, had an altercation with assistant sub-inspector (ASI) Sunil Kumar Das after which he fired a couple of rounds at the latter from his service rifle, the SP said adding that the bullets did not hit the ASI.
The enraged constable was overpowered by the escort party with the help of passengers and he was arrested after the train reached Katihar Junction, the SP said adding that the rifle has also been seized.
Investigations were on and further action may follow thereafter, Mishra said.