With time running out to save workers still trapped in a collapsed garment factory building in Bangladesh, rescuers dug through mangled metal and concrete Friday, finding more corpses that pushed the death toll past 300.

Wailing, angry relatives fought with police who held them back from the wrecked, eight-storey Rana Plaza building in the capital, Dhaka, as rescue operations went on more than two days after the structure crumbled.

Amid the cries for help and the smell of decaying bodies, the rescue of 18-year-old Mussamat Anna came at a high cost: Emergency crews cut off the garment worker's mangled right hand to pull her free from the debris Thursday night.

"First a machine fell over my hand, and I was crushed under the debris.... Then the roof collapsed over me," she told an Associated Press cameraman from a hospital bed Friday.

The search will continue into Saturday, officials said, with crews cautiously using hammers, shovels and their bare hands. Many of the trapped workers were so badly hurt and weakened that they needed to be removed within a few hours, the rescuers said.

There were fears that survivors could be badly dehydrated in stifling humidity and temperatures reaching 35 C in the daytime and about 24 C overnight.

2,200 found alive so far

Hundreds of rescuers crawled through the rubble amid the cries of the trapped and the wails of workers' relatives gathered outside the building, which housed numerous garment factories and a handful of other companies.

'They will die if we don't find them soon.'—Shahinur Rahman, son of missing worker

Brig. Gen. Mohammed Siddiqul Alam Shikder, who is overseeing rescue operations, said 2,200 people have been pulled out alive. A garment manufacturers' group said the factories in the building employed 3,122 workers, but it was not clear how many were inside it when it collapsed Wednesday in Savar, a Dhaka suburb.

Military spokesman Shahin Islam told reporters that 304 bodies had been recovered so far.

An Associated Press cameraman who accompanied a rescue crew Thursday heard the anguished cries for help from two men — one half-buried under a slab beside two corpses, the other entombed deep inside the rubble. Neither could be pulled out, and both are presumed dead, rescuers said.

Search will continue until at least Saturday

Maj. Gen. Chowdhury Hasan Suhrawardy told reporters that search-and-rescue operations would continue until at least Saturday, because "we know a human being can survive for up to 72 hours in this situation."

Forty people had been trapped on the fourth floor of the building until rescuers reached them Thursday evening. Twelve were soon freed, and crews worked to get the rest out safely, Shikder said. Crowds burst into applause as survivors were brought out.

Police cordoned off the site, pushing back thousands of bystanders and relatives after rescue workers complained the crowds were hampering their work.

Clashes broke out between the relatives and police, who used batons to disperse them. Police said 50 people were injured in the skirmishes.

"We want to go inside the building and find our people now. They will die if we don't find them soon," said Shahinur Rahman, whose mother was missing.

Thousands of workers from the hundreds of garment factories across the Savar industrial zone and other nearby areas marched elsewhere to protest the poor safety standards in Bangladesh. Local news reports said demonstrators smashed dozens of cars Friday, although most of the protests were largely peaceful.

Police say cracks in the Rana Plaza had led them to order an evacuation Tuesday, but the factories ignored the order and were operating when the building collapsed the next day. Video before the collapse shows cracks in walls, with apparent attempts at repair. It also shows columns missing chunks of concrete and police talking to building operators.

Construction concerns

Officials said soon after the collapse that numerous construction regulations had been violated.

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The disaster is the worst ever for Bangladesh's booming and powerful garment industry. (Andrew Biraj/Reuters)

Abdul Halim, an official with Savar's engineering department, said the owner of Rana Plaza was allowed to erect a five-storey building but had added another three stories illegally.

Mahbubul Haque Shakil, a spokesman for Prime Minister Sheikh Hasina, said she had ordered police to arrest the building's owner as well as the owners of the garment factories in "the shortest possible time."

Police chief Mohammed Asaduzzaman said police and the government's Capital Development Authority have filed negligence cases against the building owner, identified as Mohammed Sohel Rana.

Habibur Rahman, police superintendent of Dhaka district, said Rana was a local leader of ruling Awami League's youth front. Rahman said police were also looking for the owners of the garment factories.

Two of Rana's relatives were detained for questioning, police officer Mohammad Kawser said.

The disaster is the worst ever for the country's booming and powerful garment industry, surpassing a fire five months ago that killed 112 people and brought widespread pledges to improve worker-safety standards. Since then, very little has changed in Bangladesh, where low wages have made it a magnet for numerous global brands.

3rd largest garment industry in the world

Bangladesh's garment industry was the third-largest in the world in 2011, after China and Italy, having grown rapidly in the past decade. The country's minimum wage is now the equivalent of about $38 US a month.

Among the garment makers in the building were Phantom Apparels, Phantom Tac, Ether Tex, New Wave Style and New Wave Bottoms. Altogether, they produced several million shirts, pants and other garments a year.

Canada's Joe Fresh had some products made in the building.

The Canadian company expressed its condolences to the people affected by the collapse and said they and other apparel retailers are working to support "local efforts and provide aid and resources" in Savar.

The company will join other retailers and the Retail Council of Canada for a meeting on Monday to address the collapse and related issues.

Loblaw said in the statement that it has vendor standards aimed at ensuring its products are made in a "socially responsible" way, but the company noted there are some gaps when it comes to building safety.

"Our audits align with those of industry around the world, but we recognize that these measures do not address the issue of building construction or integrity," the company said.

Loblaw was not yet able to offer specifics on how it plans to improve the manufacturing system, but it said it is "committed to finding solutions to this situation by expanding the scope of our requirements to ensure the physical safety of workers producing our products."

The New Wave companies, according to their website, make clothing for several major North American and European retailers.

Britain's Primark acknowledged it was using a factory in Rana Plaza, but many other retailers distanced themselves from the disaster, saying they were not involved with the factories at the time of the collapse or had not recently ordered garments from them.

Wal-Mart said none of its clothing had been authorized to be made in the facility, but it is investigating whether there was any unauthorized production.

U.S. State Department spokesman Patrick Ventrell said the collapse underscored the urgency for Bangladesh's government, as well as the factory owners, buyers and labour groups, to improve working conditions in the country.

Human Rights Watch says Bangladesh's Ministry of Labour has only 18 inspectors to monitor thousands of garment factories in the Dhaka district, where much of the nation's garment industry is located.

John Sifton, the group's Asia advocacy director, also noted that none of the factories in the Rana Plaza were unionized, and that had they been, workers would have been in a better position to refuse to enter the building Wednesday.