The deceased included four members of a family.
The blast took place at the house of one Sanatan Sethi, where his family was allegedly manufacturing fire crackers illegally at Siko village under Jankia police station.
The asbestos roof of the house was severely damaged under the impact of the explosion, police said.
Fire brigade personnel went to the village and doused the fire.
The deceased were identified as Babi Sethi (40), Madhabi Sethi (8), Tikili Sethi (4), Dolly Sethi (19) and Dutee Sethi (62).