At least four people were killed and many others injured after a fire broke out at a residential building in the Bangladeshi capital, Dhaka, officials said on Friday.

The ground floor of the six-storey building where the fire broke out was also being used as a chemical storage facility, according to firefighting official Debashis Bardhman.

Local residents believe the fire may have originated at the ground floor, where the industrial chemicals were piled up.

Firefighters took four hours to bring the flame under control and found three bodies inside the building in Dhaka’s densely populated old area of Armanitola, the official said.

He added that 21 others who sustained wounds were transported to nearby hospitals.

Rescuers used forklifts to remove at least 15 residents trapped inside the building during the blaze, Bardhman said.

Professor Samanto Lal Sen, head of the burn and plastic surgery unit at Dhaka Medical College and Hospital, said one survivor had died at the hospital. No one undergoing treatment for burn injuries at the hospital is out of danger yet, he added.

The Fire Service and Civil Defence department has assigned a four-member panel to launch an investigation into the cause of the fire, said Brigadier General Sajjad Hossain, head of the department.

In February 2019, at least 70 people were killed and 55 others injured after a fire broke out in the congested neighbourhood of Chawk Bazar in the old part of Dhaka.