A scuffle broke out yesterday when more than 40 representatives of labour and human rights groups stormed the headquarters of GP Batteries. The protesters were railing against the company's alleged violation of workers' rights in Huizhou, Guangdong. Representatives from 33 organisations, including the bulletin Globalisation Monitor, the Hong Kong Christian Industrial Committee and the Hong Kong Confederation of Trade Unions, joined forces to press Gold Peak Industries - the owner of GP Batteries - to pay medical fees and other compensation to workers allegedly poisoned by cadmium at two factories. The co-ordinator of the protest, Globalisation Monitor editor Poon Man-hon, said he feared a large increase in the number of poisoned workers, which now stood at more than 100, if the company refused to improve factory ventilation. A melee broke out when the company sent security guards to bar protesters from entering its Kwai Chung headquarters. Staff tried, but failed, to shut the gate to stop protesters reaching the sixth-floor office. Five protesters overpowered them and stormed into the office. Two police officers were at the scene but no one was arrested. Protesters staged a satirical drama about how the company's factories posed a health hazard to a pregnant woman required to work 18 hours a day with minimal safety standards. A black effigy of a baby was used to signify the poisoning of her fetus. 'We demand that all workers be sent for blood tests and that the company pay all their medical fees until they have fully convalesced,' Mr Poon said. The company held a news conference yesterday evening, denying any of its workers had suffered cadmium poisoning as defined by the state's diagnostic standard. But the company's deputy general manager, Brenda Lee Wong Yuk-wan, said since the beginning of the year, 400 of its 1,000 tested workers had been found to suffer 'higher than normal cadmium levels'. However, Mrs Lee added 2,000 of its mainland staff were yet to be tested.