The cracker factory, located near Khob Darwaza area in the city caught fire around 4.45 PM, in which eight women, four men and three children were killed, Additional Superintendent of Police (ASP) Pankaj Shrivastava told PTI.
According to police, the factory belonged to one Yusuf Hussain, who was immediately detained.
The cause of the fire was yet to be known. Fire-tenders were rushed to the site, which managed to control the blaze after over an hour.