The fire had broken out Saturday evening in the cracker factory, situated near Khob Darwaza in the city, Additional Superintendent of Police (ASP) Pankaj Shrivastava told PTI.
Two more persons succumbed to their injuries on Sunday, he said.
A magisterial probe has been ordered by the District Collector in this regard, police said.
The factory belongs to one Yusuf Hussain, who was detained by police after the mishap, they said.
The fire-tenders took over an hour to control the blaze which caused panic in the area, police said.
Meanwhile, Madhya Pradesh government last night announced an ex-gratia of Rs. 1.5 lakh each to the kin of those killed in the incident and Rs. 50,000 each to the injured persons.