At least 70 people have been killed and 40 injured after a fire tore through apartment buildings and chemical warehouses in a historic part of the Bangladesh capital Dhaka, the latest such deadly blaze in the south Asian nation.

The blaze broke out Wednesday at 10:30 p.m. local time in Dhaka's Chawkbazar area, a district in old Dhaka with sprawling narrow streets and densely-packed buildings.

Throughout the night, firefighters battled the blaze, which is believed to have started when a fuel cylinder in a car exploded.

The fire then quickly spread across five buildings, including a restaurant, Ibrahim Khan, deputy commissioner of Dhaka Police told CNN.

Firefighters are seen at the scene of a fire in Dhaka on February 21, 2019.

Among the dead were customers of the restaurant who were caught in the fire, said Khan.

Inspector Morad Dul Islam from Chawkbazaar police station said that they do not yet have an estimate on the number of people injured but they are transferring them to nearby hospitals.

One of the structures served as a warehouse for a perfume company. Plastics and chemicals that were being stored to manufacture the perfume ignited in the blaze that destroyed two buildings.

Firefighters try to douse flames in Dhaka, Bangladesh on February 20, 2019.

Khan said the fire is now under control.

"In the morning we were able to control the fire. The fire is now over," he said.

Authorities began the process of identifying victims Thursday, as relatives waited at the Dhaka College Hospital for news of their loved ones.

"When we are able to search the whole building then we will know the exact numbers of victims," said Lieutenant Colonel Zulfikar, fire brigade director.

Built over 400 years ago, Chawkbazar is a commercial and industrial hub in the old city of Dhaka that's known for it's food. Over the past few decades its population has mushroomed with houses and apartments built on top of warehouses and factories over narrow, winding streets.

Electric wires hang low over the over narrow, winding streets that are filled with rickshaw drivers and vendors.

Source: CNN