Fire sweeps through multi-storey building as factory workers slept inside in a congested area of India’s capital.

At least 43 people have died in a devastating fire in a multi-storey building housing a factory in a congested market area of India‘s capital New Delhi, officials said.

The blaze broke out at about 4am local time on Sunday (22:30 GMT on Saturday) in the city’s old quarter, whose narrow lanes are lined with many small manufacturing and storage units.

Monika Bhardwaj, deputy police commissioner of New Delhi’s north district, told AFP news agency that the death toll from the incident had jumped to “43, with 16 others still admitted at the local hospitals”.

“Fire department has completed the rescue work. There are no more bodies at the site,” said Bhardwaj. “We don’t yet know the cause of fire but know that it was aggravated because of plastic packing pouches, bags and other such material there.”

A fire engine stands by the site of a fire in an alleyway, tangled in electrical wire and too narrow for vehicles to access, in New Delhi [Manish Swarup/AP]

Fire officials said it was very difficult to access the dark, poorly-lit premises in the commercial hub of Sadar Bazar in the older part of the capital.

Firefighters fought the blaze from 100 metres away because it broke out in one of the area’s many alleyways, tangled in electrical wire and too narrow for vehicles to access, authorities at the scene said.

Fire Services Chief Atul Garg said the blaze was put out by 25 fire trucks and that the rescue operation was completed. About 60 people, including casualties, were taken out of the building, officials said.

Workers slept in factory

While the cause of the fire is not clear, police and fire officials said they were investigating whether a manufacturing unit was operating illegally in the crowded area.

They were “labourers and factory workers sleeping inside this four- or five-storied building,” said Sunil Choudhary, New Delhi’s deputy chief fire officer.

Reporting from New Delhi, Al Jazeera’s Anchal Vohra said the factory in the crowded market hired “cheap labour who were made to work long hours”.

“The labourers slept in the factory during the night. The fire took place early in the morning, so they were inside the factory when this happened,” she said.

Most of those dead in the fire were migrant workers who slept in the factory [Bilal Kuchay/Al Jazeera]

Zakir Hussain, 32, said he lost his 28-year-old brother, Shakir, in the deadly blaze.

Shakir, a father of four, made caps in the factory. The two brothers were migrant workers from the eastern state of Bihar and came to New Delhi eight years ago.

“I got a call at around 4am … that the building had caught fire and I am inside my room and there is no way to leave the room,” Zakir recalled Shakir saying.

“I reached the building at 4:30am. I called his phone several times, but nobody picked the phone,” he said.

Close by, Mahboob Alam was in tears. He said he made handbags with two of his nephews – Mohammed Imran and Ikram-ud-Din – and they lived on the second floor of the building.

“My nephews are missing. I visited a couple of hospitals and looked for them among the dead and injured, but so far no news,” he told Al Jazeera.

“Now, I have come here to LNJP [Lok Nayak Jai Prakash] hospital, but the police is not allowing me to go inside,” he said.

Mohammad Mukhtar who lost his nephew outside the hospital mortuary in New Delhi [Bilal Kuchay/Al Jazeera]

Mohammad Mukhtar broke down outside the hospital mortuary after hearing that his 35-year-old nephew, Zahid Ahmad, is dead.

Ahmad, a father of three children, made jackets at the factory. His younger brother, Mohammad Ayub, 31, was also with him in the building. There is no information about Ayub yet.

‘Extremely horrific’

“The fire in Delhi’s Anaj Mandi on Rani Jhansi Road is extremely horrific. My thoughts are with those who lost their loved ones,” Prime Minister Narendra Modi posted on Twitter.

“Wishing the injured a quick recovery. Authorities are providing all possible assistance at the site of the tragedy,” he added.

Arvind Kejriwal, the chief minister of Delhi, described the incident as “very very tragic news” and announced a compensation of a million rupees ($14,000) for the families of the dead.

We have lost more than 40 innocent lives to the tragic fire. I've ordered a magisterial inquiry into its cause, no culprit will be spared We can't bring back lost lives, but Delhi govt will provide ₹10 L assistance to families that lost their loved ones & ₹1 L for the injured. pic.twitter.com/SOT5kR9l5J — Arvind Kejriwal (@ArvindKejriwal) December 8, 2019

Al Jazeera’s Vohra said the Delhi government has ordered an inquiry into the incident.

“The case has been transferred to the crime branch of the police, so that is sort of an indication that the government is trying to send a message that they are taking this seriously,” she said.

Fires are common in India, where building laws and safety norms are often flouted by builders and residents.

Many factories and small manufacturing units in big Indian cities are often located in old, cramped quarters of the cities, where the cost of land is relatively cheaper.

Such units often also serve as sleeping quarters for poor, mostly migrant labourers and workers, who manage to save money by sleeping overnight at their workplaces.

In 1997, a fire in a movie theatre in New Delhi had killed 59 people. In February this year, 17 people were killed by a fire in a six-storey hotel, also in the Indian capital that started in an unauthorised rooftop kitchen.

Bilal Kuchay contributed to this report from New Delhi