More than 50 people have been killed and about 100 injured in a fire at a textile mill in Bangladesh, police say.
Soldiers were brought in to take over rescue work from firefighters after the fire reduced the building to rubble.
Two officials involved in running the mill in the south-eastern port city of Chittagong have been arrested and are being questioned, police said.
At least 500 workers were inside the mill when the fire broke out. Officials are trying to establish the cause.
Bangladeshi Prime Minister Khaleda Zia on Friday visited the scene of the fire and a hospital where the injured were being treated.
Officials said she had ordered a thorough investigation into the fire, and asked the authorities to compensate the families of those killed and help rehabilitate the injured.
Dozens of garment workers and human rights activists marched through the capital, Dhaka, demanding better safety in factories and proper compensation for the victims, the BBC's Waliur Rahman in Dhaka says.
Mill workers marched in Dhaka to demand improved factory safety
The blaze has been described by officials as the country's worst ever factory fire, he adds.
Most of the survivors had to jump from windows as the only exit from the factory was reportedly locked when the fire broke out late on Thursday, a fire department official, Rashidul Islam Majumder, told the BBC.
No representatives of the KTS Textile Mills were available for comment.
Police said one of those arrested was a director of the textile firm.
The death toll rose to 52 on Friday, as rescue workers recovered more bodies from the debris.
Most of the victims were women, who were trapped by the flames or suffocated from smoke inhalation.
Initial reports suggested that the fire might have been caused by an electrical short circuit.
"The main gate was locked when we heard a loud noise followed by fire and an electricity cut," a factory worker told a Bangladesh television station.
"Some neighbours cut open the window grilles to help us out of the factory," he added.
Rescuers said the fire had spread quickly through the building because of stacks of yarn piled up on the floors.
The explosion of a boiler escalated the blaze, witnesses said.
Rescuers said the blaze was Bangladesh's worst industry fire
A doctor at a local hospital told AFP that 25 people were in a critical condition.
Textiles make up about 85% of Bangladesh's exports, earning the country some $6bn (£3.4bn) annually.
However, the industry has been plagued by accidents due to poor safety standards.
In 2000, at least 48 workers died when a locked fire exit left them trapped in a burning factory near the capital, Dhaka.
Last April, more than 60 people died when an illegally-constructed garment factory collapsed.
What is your reaction to news of the fire at the textile mill? Did you witness the blaze or do you know anyone affected by it? Send us your comments and experiences.
The BBC may edit your comments and not all emails will be published. Your comments may be published on any BBC media worldwide.