The Foxconn factory in the southern Chinese boom town of Shenzhen is so vast that walking around its outer perimeter takes two hours. Its workers turn out components that are supplied to big Western electronics brands including Nokia, Hewlett-Packard and Dell. And it is here that most of the parts for Apple's iPhone, and the much-awaited iPad, which goes on sale in the UK this week, are manufactured.

Yesterday, Li Hai, a 19-year-old employee of the firm, jumped from the top of the building in Shenzhen to his death. It brought the number of suspected suicides at the factory this year to 10. There have been another two attempted suicides.

All of the deaths have been of youngsters between 18 and 25 years old. Li Hai had only been working at the plant for 42 days. The incidents have prompted intense soul-searching in China, about conditions in its factories and the social cost of breakneck economic development.

Foxconn, one of the world's largest manufacturers of electronic equipment, is huge. The chefs slaughter 6,000 pigs a day to feed the company's nearly 400,000 workers in this giant industrial complex, spread over 1.2 square miles.

But the Taiwanese owners now face a major problem. Li Hai's death, and those of his colleagues, have raised questions about working conditions in Chinese factories, with labour activists alleging that long hours, low pay and high pressure make for an unbearable working environment.

Chinese media have suggested that what is driving the suicides is the feeling among the workers that they are machines. Many start work at 4am, then go through the motions thousands of times over during their often long shifts. "Every shift we finish 4,000 Dell computers, all the while standing up," one Foxconn worker told China Labour Watch for a recent report.

In July, a Foxconn worker committed suicide when the company held an inquiry into the disappearance of an iPhone prototype, for which he had had been considered responsible. The founder of Foxconn's parent company in Taiwan, Hon Hai Precision, Terry Gou denied that his factories were sweatshops and he was confident the situation would be resolved soon.

The company, which employs over 800,000 workers around the world, is now playing soothing music along the production lines. Over 2,000 singers, dancers and gym trainers have been recruited, and the group is also hiring psychiatrists and Buddhist monks to help with stress. New fences are also being installed on every worker's dormitory building, according to local media, which are up to three metres high and are meant to prevent suicidal workers from jumping off the roof.

But local media said the workers, many of whom are migrants and isolated from their home communities, found the fences even more depressing. "Young workers born during 1980s or 1990s are becoming the mainstream of our workforce. In this context, the Foxconn employee 'jumping' incidents should arouse the vigilance of the whole society. Companies, government and society should pay more attention to the spiritual crisis of young lives," said the Xinhua news agency in an editorial.

Zhang Ming, a political science professor at the People's University of China, said workers were reacting to feeling as if they were machines or spare parts. "To many post-Eighties or post-Nineties migrant workers, it is unbearable for them to live in a place without cultural entertainment and communications with their friends. They are psychologically weak. The Foxconn 'jumping' incident is a call for life."

One worker told the Southern Weekend newspaper that he would deliberately drop something on the ground so that he could have a few seconds of rest when picking it up.

Nine mainland Chinese and Hong Kong academics have issued an open statement calling on Foxconn and the government to do more for the workers. "China's development strategy throughout these 30 years not only accomplished an economic miracle, it deepened regional inequalities, prolonged stagnation of wages, and deprived migrant workers' citizenship and human rights," it said.