At around 4.30 am, a fire broke out in the kitchen and engulfed the train. The train was then halted at Dharamtul Station.
Trains on the Guwahation and Lumding railway track were stopped for 3 hours, police and Railway sources said.
Fire tenders fought for two hours to douse the flame, the sources said. The railway track was cleared at 8 am after the fire was completely doused but the train was still in the station, they said.
There were at least 15 people, including the pantry car staff, in the coach when it was engulfed in flames. All of them escaped unhurt.
"Fire brigade rushed to the area and later doused the fire with help from police and local people. The details of the incident are awaited but it is suspected that some kind of short circuit led to the incident," said the Northeast Frontier Railway (NFR) spokesman.
Dharamtul is located about 70 km from Assam's main city Guwahati.
The train left Dibrugarh station at 8.30 p.m. Monday night and was scheduled to arrive at Guwahati Tuesday morning at 6.40 a.m.
Senior railway official have rushed to the spot.