Passengers of the Howrah-Guwahatidown Garibrath Express had a providential escape on Sunday when a powerful bomb exploded on the railway tracks minutes after it passed Goabari in lower Assam's Kokrajhar district.
There was no casualty or injury.
The bomb suspected to have been planted by the anti-talk faction of the National Democratic Front of Bodoland (NDFB) exploded at 1.10am two minutes after the train passed the area between Gossaigaon and Fakiragram, police said.
The blast blew away three feet of railway track and left a two feet deep crater at the spot, they said.
Initially, train services were affected for about five hours. But the line was repaired and train services restored in the morning.
As the railway line is a double track one, the trains scheduled to pass over the damaged track were diverted to the adjacent one, railway sources said.
Security forces have launched a search operation to nab the ultras.