A devastating fire has raced through densely packed buildings in a centuries-old shopping district in Bangladesh’s capital, killing 67 people, officials said.

The fire in Dhaka’s Chawkbazar area was mostly under control after more than 10 hours of frantic firefighting efforts.

Some of about 50 people who were injured were critically burned.

The district dating to the Mughal era 400 years ago is crammed with buildings separated by narrow alleys, with residences commonly above shops, restaurants or warehouses on the ground floors.

Residents of the Muslim-majority nation throng to Chawkbazar each year for traditional goods to celebrate iftar, the end of Ramadan.

The blaze started late on Wednesday in one building but quickly spread to others, fire department chief Brigadier General Ali Ahmed said.

Many of the victims were trapped inside the buildings, said Mahfuz Riben, a control room official of the Fire Service and Civil Defence in Dhaka.

“Our teams are working there but many of the recovered bodies are beyond recognition. Our people are using body bags to send them to the hospital morgue, this is a very difficult situation,” he said.

Bangladesh FireFirefighters and local people gather near smouldering buildings in Dhaka (AP)

A duty officer for the Dhaka fire department said authorities had earlier counted 81 dead.

Russel Shikder said a later careful review at a morgue where those killed were taken tallied 67 dead.

First responders were delayed reaching the site partly because nearby roads were closed for national holiday commemorations on Thursday.

Just after midnight as the fire blazed, Bangladesh’s prime minister and president laid wreaths at a monument less than a mile away to commemorate protesters who died in a 1952 demonstration for the right to speak Bengali, the local language.

Fire officials said the road closures worsened traffic, slowing down some of the fire engines rushing to the site.

Bangladesh FireFirefighters try to douse flames in Dhaka (AP)

Most buildings in Chawkbazar are used both for residential and commercial purposes despite warnings of the potential for high fatalities from fires after one killed at least 123 people in 2010.

Authorities had promised to bring the buildings under regulations and remove chemical warehouses from the residential buildings.

A government eviction drive in Chawkbazar and other areas of Old Dhaka was met with protests last May right before Eid, the beginning of Ramadan, by business owners and residents.

Bangladesh FireFirefighters gather around buildings that caught fire late (Rehman Asad/AP)

In 2012, a fire raced through a garment factory on the outskirts of Dhaka, killing at least 112 people trapped behind its locked gates.

Less than six months later, another building housing garment factories collapsed, killing more than 1,100 people.

The death toll from the latest fire could rise as the condition of some of the injured people is critical, said Samanta Lal Sen, head of a burn unit at Dhaka Medical College Hospital.

Witnesses told local TV stations that many gas cylinders stored in the buildings continued to explode. They said the fire also set off explosions in fuel tanks in some of the vehicles that got stuck in traffic in front of the destroyed buildings.

Some reports suggested many of the dead were pedestrians, shoppers or diners who died as gas cylinders exploded, and the fire engulfed nearby buildings.