DHAKA - A fire swept through a garment factory on the outskirts of Bangladesh's capital killing more than 100 people, the fire brigade said on Sunday, in the country's worst ever factory blaze.

Firefighters try to control a fire in a garment factory in Savar, on the outskirts of Dhaka November 24, 2012. [Photo/Agencies]

Working conditions at Bangladeshi factories are notoriously poor, with little enforcement of health and safety laws and overcrowding and locked fire doors common, but the cause of this fire was not immediately known.

The blaze at the nine-storey Tazreen Fashion factory in the Ashulia industrial belt of Dhaka started on the ground floor late on Saturday and spread, trapping hundreds of workers.

"So far, the confirmed death toll is 109, including nine who died by jumping from the building," Mizanur Rahman, deputy director of the fire brigade, told Reuters.

Witnesses said the workers, mostly women, ran for safety as the fire engulfed the plant, but were unable to get through narrow exits.

A firefighter tries to control a fire at a garment factory in Savar, outskirts of Dhaka November 24, 2012. [Photo/Agencies]

"Many jumped out from the windows and were injured, or died on the spot," Milon, a resident, said.

Unofficial sources put the number of dead at more than 120, saying the toll may be higher. Most of the bodies were found on the second floor, Rahman said.

Bangladesh has around 4,500 garment factories and is the world's biggest exporter of clothing after China, with garments making up 80 percent of its $24 billion annual exports.

This was the highest ever death toll in a Bangladeshi factory fire. In 2006, 84 people were killed in a blaze in the southern port of Chittagong where fire exits had been blocked.

More than 300 factories near the capital shut for almost a week earlier this year as workers demanded higher wages and better working conditions.