Officials in Bangladesh say at least 150 people are now known to have died after an eight-storey building near the capital Dhaka collapsed.
Some 2000 people were in the Rana Plaza building in Savar, which houses several clothing factories, a bank and a market when it collapsed suddenly on about 9am on Wednesday (local time).
More than 1000 have been injured and many more people remain trapped. A frantic search for survivors in the rubble is continuing. Rescue teams with sniffer dogs are working with volunteers, using heavy machinery and their bare hands to free people on Thursday.
Officials said that so far, about 400 people have been rescued. Tens of thousands of weeping family members are gathered at the site, the BBC reports.
Police said the factory owners had ignored warnings not to allow their workers into the building after cracks were noticed on Tuesday. The owners are now said to have gone into hiding.
Police said the rear of the building suddenly started to collapse on Wednesday morning and within a short time the whole structure - except the main pillar and parts of the front wall - had caved-in. Officials said only the ground floor of the building remained intact.
The disaster has prompted questions over Bangladesh's chronically poor safety standards.
Bangladesh has one of the largest garment industries in the world, providing cheap clothing for major Western retailers which benefit from its widespread low-cost labour.
Prime Minister Sheikh Hasina has announced a national day of mourning on Thursday in memory of the victims.