AT least 81 people were killed when fire tore through crumbling apartment blocks in a historic part of Dhaka, setting off a chain of explosions and a wall of flames down nearby streets, officials said Thursday.

It started in one building where chemicals for deodorants and other household uses were illegally stored and spread at lightning speed to four nearby buildings, the fire service said.

People became trapped by the flames at a nearby bridal party and a restaurant. TV images showed the gates to one building were chained up so residents were unable to escape.

Traffic jams in the clogged narrow streets held up the rescue operation.

Doctors said at least 10 of the scores of injured were in critical condition.

Firefighters who took almost 12 hours to bring the fire under control, went through the blackened floors of the building, littered with spray cans, looking for bodies.

The fire started at about

10:40 p.m. Wednesday at Chawkbazar in the old Mughal part of the capital.

Bangladesh fire chief Ali Ahmed said it may have been started by a gas cylinder and quickly spread through the building where chemicals were stored in rooms alongside the apartments.

Chemicals used for household products were also stored in the nearby buildings. They exploded as the fire spread, witnesses said.

“There was a traffic jam when the fire broke out. It spread so quickly that people could not escape,” the fire chief said.

Another fire official told reporters the blaze was under control but was not extinguished despite the efforts of more than 200 firefighters.

“It will take time. This is not like any other fire,” he said, adding that the inferno had been made more devastating by the “highly combustible” chemicals.

Fire trucks had struggled in the narrow streets to reach the scene and there was also a lack of water for the battle, officials said.

The main gate of one five story building was chained up, trapping residents inside, according to images shown on Bangladesh television. (SD-Agencies)