An IED blast led to derailment of Guwahati-Puri Express in Kamrup district of Assam.
The Home Ministry said that a group known as the Adivasi People's Army has claimed responsibility.
There has been no full-time railway minister since May 2011 and several key posts are lying vacant.
A special train with 800 passengers of the Guwahati-Puri Express left Guwahati for Puri at 5:30 am on Monday.
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