Suspected NDFB (Daimary faction) militants exploded an Improvised Explosive Device (IED) on the railway tracks at Deka Mising Gaon in Dhemaji district early on Sunday, police said.
There was no casualty as night movement of trains was suspended by NF Railways between January 24 and January 27 due to security reasons.
The IED was suspected to be planted by the NDFB militants for subversive activities in the run-up to the Republic day.
Parts of the railway track have been damaged, Superintendent of police S R Hazarika said.
Hazarika suspected the NDFB faction to be behind the blast as their extortion attempts are carried out in Jonai-Telem and Deka-Palm areas, 10 km from the spot where the IED exploded between 3.30 am and 4 am.