Dhaka: Bangladesh on Tuesday called off a search for survivors after an explosion at a garment factory killed at least 13 workers and injured scores, the latest disaster to hit the multi-billion dollar industry.

Dozens of workers were inside the factory on the outskirts of Dhaka when the boiler exploded on Monday evening, causing a section of the six-storey building to collapse.

It was unclear what caused the explosion, which occurred during maintenance work on the boiler at a time when most of the factory's 5,000 workers were off for the Eid holidays.

Authorities called off the nearly 22-hour-long search after rescuers found two more bodies in a toilet next to the destroyed boiler room, bringing the death toll to 13.

"Our fire fighters have completed searching the entire section of the debris," local administrator Mahmud Hasan told AFP.

The government said it had formed a committee to investigate the explosion, the latest disaster to strike the country's $30-billion garment industry.

The plant in the Gazipur industrial district is owned by manufacturer Multifabs, which makes clothing for brands including Littlewoods and Aldi according to its website.

The collapse of the nine-storey Rana Plaza factory complex in April 2013 in which more than 1,100 people were killed was seen as a wake-up call for the industry, which supplies clothing for major brands all over the world.

In the wake of the disaster, authorities pledged to improve working conditions at factories but accidents are still commonplace.

Only a few hundred of the country's 4,500 textile factories have been certified as safe and last year a fire at a factory just miles from Rana Plaza claimed 34 lives.

A survey this year by global charity Action Aid of more than 1,400 Rana Plana survivors found nearly half were still jobless while roughly 31 percent were too traumatised to work.

There have also been demands for an increase in the basic monthly wage of $68 for the country's four million garment workers, most of whom are young women.

One of the injured workers receiving treatment at nearby hospitals blamed the factory authorities for not replacing the boiler despite the fact that it was allegedly "beeping danger signals continuously".

Worker Harunur Rashid told Bangla daily Prothom Alo that the boiler's safety bulb was beeping danger lights but the device's operators assured them there was nothing to worry about.

"Within ten minutes after we returned to work, the boiler exploded. It's absolutely the authorities' negligence," he said.

Mesba Faruqui, the operations director of the factory, said the operators were doing maintenance duty as the factory was meant to open on Tuesday after the long Eid holidays.

"If the accident had happened today, God forbid, there might have been many more casualties," he told AFP.