Railways sources told IANS that the incident occurred on the Lucknow-Rameswaram Express.
All the six victims hailed from Uttar Pradesh, the sources said, adding that there were a total of 55 passengers in the affected coach.
The fire erupted following attempts to cook food, the sources told IANS.
Fire personnel from Madurai arrived on the scene and doused the blaze.
Additional details are awaited.
–IANS
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