The tank exploded during cleaning at the six-storey building near Moraparha Bihari Camp at block-E in the area around 9pm on Tuesday.
A local, who identified himself only as ‘Shakil’, brought the injured to the Dhaka Medical College Hospital.
The victims are the building’s owner Mosharraf Hossain, 45, his son ‘Jisan’, 18, tenants Awal Hossain Babu, 32, Surat Ali, 60, his wife Bedana Begum, 40, their daughter ‘Aleya’, 25, Alayea’s daughter ‘Mily’, 5, Alaeya’s brother ‘Rabbi’, 20, and his wife ‘Laboni’, 18.
They have been admitted to the hospital’s burns unit, said Babul Mia, an assistant sub-inspector at the hospital’s police camp.
Quoting Shakil, the policeman said the tank exploded with a loud bang, triggering a fire.
MO Ershad, a Fire Service official, said they suspect gas from a leaked pipe beneath the tank caused the explosion.