Police said the blast, suspected to be caused by an IED, was triggered between Central Market and Lakshmi talkies in the heart of the headquarters town of Sibsagar district at 9 pm.
Eight people were hurt and taken to Sibsagar Civil Hospital or another private hospital nearby and one of the injured Nirod Das (32) later died at the civil hospital.
Glass panes of some nearby constructions were broken by the impact of the blast.
The blast could have caused higher casualty had it taken place an hour ago when the place was teeming with people.
Army and security personnel visited the spot.