Tens of thousands of Bangladeshis joined May Day protests on Wednesday to demand the execution of textile bosses over the collapse of a factory complex, as rescuers warned the final toll could be more than 500. Despite calls by the prime minister for “cool heads”, tensions over the country’s deadliest industrial disaster showed little sign of abating and there were fears of more violence and vandalism at textile mills. Workers holding red banners and flags chanted “Hang the killers, Hang the Factory Owners” as they took to the streets of Dhaka at the start of a series of nationwide demonstrations during the public holiday. Police put the number of protesters at the main rally in Dhaka at more than 20,000, and there were smaller-scale protests elsewhere in the capital and in other cities. Kamrul Anam, one of the leaders of the Bangladesh Textile and Garments Workers League, said the demonstrators were angry at “the murder” of their colleagues in the April 24 disaster at Savar on the outskirts of Dhaka. “We want the severest punishment possible for those responsible for this tragedy,” he said. “Enough is enough,” said Liakot Khan, another of those taking part in the Dhaka protest, which echoed to the sound of drums and horns. “The government should hang the proprietor and the factory owners. We want justice for these murders.” The Bangladesh government is also facing foreign pressure to take credible moves to raise safety standards in the garment industry, with the collapse at the Rana Plaza factory complex only the latest in a series of deadly disasters. The government should hang the proprietor and the factory owners. We want justice for these murders The European Union said late on Tuesday that it would look at steps to promote better practices in a sector that depends on Western brands, with clothes from retailers Primark, Benetton and Mango manufactured recently at the site. With bulldozers busy clawing through the ruins of the eight-storey complex, military spokesman Mir Rabbi said that the confirmed death toll now stood at 402. An army general also told reporters that local officials had drawn up a list of 149 people who are still unaccounted for. A total of eight people have so far been arrested and charged with “death by negligence” over the collapse of the eight-storey building which housed five separate garment factories. Those charged, who include the overall owner of the building as well as engineers who had given the building the all-clear after cracks were reported, have had to wear bulletproof vests at their court appearances. Tensions have been further heightened by regular clashes between hardline activists and the police who have been using teargas and rubber bullets to disperse crowds of protesters. Many of the country’s 4,500 garment factories have been closed since last Wednesday, a major blow for the Bangladeshi economy which is powered in large part by the US$20 billion industry. Speaking to parliament on Tuesday night, Prime Minister Sheikh Hasina urged employees to return to work and criticised reported attacks on some factories. “I would like to tell the workers to keep their head cool, keep mills and factories operative, otherwise you will end up losing your jobs,” she said. The United Nations revealed on Tuesday that it had offered to fly in specialist rescue teams only hours after the collapse but Hasina’s government had decided to handle the operation on its own. The deputy director general of the UN’s International Labour Organisation, Gilbert Houngbo, was expected in Dhaka on Wednesday to discuss with the government how to improve safety standards. A fire at a textile factory last November left 111 people dead, and there have been widespread accusations that safety standards are both too lax and rarely enforced. Campaigners say Western retailers who source their clothing to Bangladesh must also take a share of the blame. Senior European Union officials said Brussels was ready to help Bangladeshi authorities meet international standards and urged foreign companies to promote better health and safety standards in garment factories in Bangladesh. “The European Union calls upon the Bangladeshi authorities to act immediately to ensure that factories across the country comply with international labour standards,” EU foreign affairs chief Catherine Ashton and Trade Commissioner Karel De Gucht said in a statement.