Garment workers in Bangladesh staged mass protests on Monday to demand the end of "deathtrap" labour conditions after the country's worst-ever textile factory fire in which 110 employees died.
Survivors of Saturday night's fire joined several thousand colleagues blocking a highway during a march in the manufacturing hub of Ashulia, outside the capital Dhaka, with some protesters throwing stones at one factory.
Bangladesh's chief inspector of factories Habibul Islam told AFP that the nine-storey Tazreen factory where the blaze broke out, which was built in 2009, had permission for only three storeys.
"They expanded the building without our approval," he said.
Ashulia's more than 500 factories, which make apparel for top global retailers such as Walmart, H&M and Tesco, declared a "holiday", fearing that the protests could worsen and turn into large-scale unrest.
"Most workers are in shock. They want to see safety improvements to these deathtrap factories," Babul Akter, head of a garment union, told AFP.
The protesters chanted slogans, including a demand for Tazreen's bosses to be brought to justice.
Local police chief Badrul Alam said officers had opened a murder investigation as a result of criminal negligence.
Two government inquiries and the police investigation are trying to establish if the owners were to blame for the fire, though the cause has not yet been determined.
"We won't spare anyone," Alam promised as the Prime Minister Sheikh Hasina announced a day of mourning for the dead on Tuesday, when all factories will also be closed.
Dozens of workplace fires have now killed more than 600 employees in Bangladesh's booming garment industry since 2006, according to the Clean Clothes Campaign, a Amsterdam-based textile rights group.
But none of the owners have so far faced prosecution for poor safety conditions.
Firefighters battled for several hours to contain the blaze, which broke out on the ground floor of the Tazreen Fashion plant 30 kilometres (20 miles) north of Dhaka, trapping over 1,000 workers.
Witnesses told how desperate workers, most of them women, cried for help and several leaped to their deaths from upper floors as they tried to escape.
A mass burial of the bodies of 58 workers was postponed until Tuesday after request from their relatives who want more time for identification.
"They will be buried at a state graveyard in Dhaka Tuesday morning," Dhaka district commissioner Yusuf Harun told AFP.
"We are keeping the DNA samples of the dead workers so that we can identify their relatives for compensation."
Another blaze on Monday at a 12-storey building housing four garment factories sparked fresh scenes of panic as workers rushed to safety.
The latest fire caused widespread damage and rescue teams searched the building for workers feared to have suffocated but there were no casualties.
"Most workers broke grills in the upper floor and escaped to a safe location at an adjacent building,"
Dhaka district deputy commissioner of police Nisharul Arif told AFP.
Bangladesh has emerged as the world's second-largest clothes exporter with overseas garment sales topping $19 billion last year, or 80 percent of national exports.
The sector is the mainstay of the poverty-stricken country's economy, employing 40 percent of its industrial workforce, but work conditions are often basic and safety standards low.