The blast took place about 290 kilometers east of Assam's main city of Guwahati.

Police blamed the blast on the outlawed Karbi Longri National Liberation Front (KLNLF), which observed the anniversary of its foundation on Saturday.

The rebel group, fighting for an independent homeland for the majority Karbi tribe, has claimed responsibility for Tuesday's train bombing in the state which killed three and injured 30.

In separate incidents in the state, army soldiers killed three militants of the outlawed United Liberation Front of Asom (ULFA) in three gunfights. -- AFP