A fire broke out in the locomotive of the Samastipur–Saharsa passenger train early Monday while it was standing at Simri Bakhtiyarpur station in Bihar's Saharsa district.
The train had reached platform 2 at about 3:25 a.m. when smoke was seen coming from the engine.
Flames then spread from the locomotive to three coaches.
The three coaches were destroyed in the fire.
Passengers left the train after the fire was detected.
Police and fire services were deployed to the station.
Firefighting continued for about two and a half hours; accounts differ on whether the blaze was fully or only partly under control by then.
Rail services were disrupted, with some passenger trains cancelled and special trains delayed.
The station superintendent said rail services were affected for some time before operations returned to normal from around 6 a.m.
Police have identified a short circuit as a preliminary possible cause, while railway authorities are examining whether the locomotive had a technical fault.
Police and railway authorities are investigating the cause of the fire.