The blast that had taken place on May 4 night, about 20 km from here, killed four persons, including an 18-year-old boy and left two seriously injured.
Two injured women were admitted to hospital and one of them died today, police said.
The workers had been making crackers when the explosion occurred, triggering a fire in the unit.
The factory owner, who had been absconding after the explosion occurred, was arrested, police said.