The fire broke out in a building with shops on its ground floor, a warehouse for plastics and flammable material on the first, and homes on three floors above, said Shamim Harun ur Rashid, a local police official.
Firefighters work to douse flames in Dhaka, Bangladesh, Thursday, Feb. 21, 2019.
Fire Service and Civil Defence spokesman Julfikar Rahman told reporters earlier this morning before the death toll went up: "So far, 56 bodies have been recovered".
Hundreds of burnt perfume or deodorant cans littered the road near the partially collapsed building where the fire began, a Reuters witness said.
A Bangladeshi boy cries as he carries the coffin of a relative who died in the fire.
The blaze started late Wednesday night in one building and quickly spread to others, fire department director general Brig.
Most buildings are used both for residential and commercial purposes, despite warnings of the potential for high fatalities from fires after a blaze killed at least 123 people in 2010.
According to local media, the fire also spread to nearby buildings. "Our people are using body bags to send them to the hospital morgue, this is a very hard situation". Proceedings have dragged however, and prosecutors say a verdict could take five more years.
It took almost 200 firefighters and more than five hours to contain the blaze in the area which, locals claimed, was home to more than three million people. Authorities had promised to bring the buildings into line with regulations and remove chemical warehouses from the residential buildings.
Doctors said at least 10 of the scores of injured were in critical condition.
Numerous victims were trapped inside the buildings.
Witnesses told local TV stations that many gas cylinders stored in the buildings continued to explode one after another.
According to the divisional commissioner, 41 people are undergoing treatment at different hospitals in the city and the bodies have been kept at the Dhaka Medical College Hospital morgue. "This is not like any other fire", he said, adding the inferno became so devastating due to the "highly combustible" chemicals stored there.
The death toll now sits at 70 but fire officials expect it to rise as the fire tore through the building and leapt to four others, some of which also stored chemicals, at the tight intersection.