The injured were garment workers Akram Hossain, his wife Lovely Akhter and their eight-year old son Ashiqur Rahman, hailing from Madhukhali in Faridpur district.
Humayun Kabir, station officer of Ashulia DEPZ Fire Service and Civil Defence Station, said the gas spread all over in their room in a building owned by Mostafa Dewan in Pashchim Bypile area following a leakage in the gas line of the cylinder.
When one of the victims Lovely Akhter tried to ignite the stove for cooking around 5:00 am, the fire originated and the gas cylinder blasted with a bang soon it came into contact with the fire, said the station officer.
Hearing screaming of the house inmates, locals rescued them and took to a local hospital. As their condition deteriorated, they were shifted to Dhaka Medical College Hospital (DMCH).
The fire also damaged an electronic shop adjoining to the house, he added.