The owner of the factory has been named in a police case, but is yet to be arrested.
Security camera footage showed the explosion at a factory in western Uttar Pradesh's Hapur district that left 13 people dead and at least 16 injured on Saturday.
There were around 30 people in the affected area at the factory in the UPSIDC industrial area in Dholana, around 80 km from the national capital, when the incident occurred, the police have said.
The impact of the explosion was so intense that the roofs of some factories located in the vicinity were damaged. It took three hours for fire tenders to douse the blaze.
Officials have said that the factory was given a licence to manufacture electronic items, however, it had been manufacturing firecrackers.
The owner of the factory has been named in a police case, but is yet to be arrested.
President Ram Nath Kovind, Prime Minister Narendra Modi and Uttar Pradesh Chief Minister Yogi Adityanath expressed grief over the loss of lives.
The Chief Minister directed that the incident be probed by experts.
In a statement issued in Lucknow, Adityanath asked the district administration to extend all possible help to the family of those killed and injured.