This was the first major incident of violence after the Manipur assembly elections were announced.
Two days before voting in Manipur, at least two people including a child were killed and five others injured in an explosion at a house in Churachandpur district on Saturday night.
The explosion in Gangpimual village appeared to have been caused by a mortar.
A district police official said that seven people including children were seriously injured in the blast and taken to the district hospital, where Mangminlal, 6 and Langinsang, 22, died of their injuries.
Senior police officials and reinforcements have rushed to the area and a search was on to catch those responsible.
Saturday night's bomb explosion was the first major incident of violence after the Manipur assembly election dates were announced on January 8.
The elections to the 60-seat Manipur assembly will be held in two phases on Monday and Saturday. Votes will be counted on March 10.