Young Foxconn workers who normally spend their days assembling iPhones and other high-tech gadgets packed a stadium at their massive campus on Wednesday, waving pompoms and shouting slogans at a rally to raise morale following a string of suicides at the company's heavily regimented factories.

The outreach to workers shows how the normally secretive Foxconn Technology Group has been shaken by the suicides and the bad press they have attracted.

"For a long period of time I think we were kind of blinded by our success," said Louis Woo, special assistant to Terry Gou, the founder of Foxconn's parent company. "We were kind of caught by surprise."

The company has already raised wages, hired counsellors and installed safety nets on buildings to catch would-be jumpers. Other changes include job rotation so workers can try different tasks and grouping dorm assignments by home province so workers do not feel so isolated.

However, Mr Woo acknowledged there will be challenges in preventing such tragedies in a work force of 920,000 spread across 16 factories in China, all of which are to have morale boosting rallies. He added he expected the company will grow to 1.3 million workers sometime next year.

The rally on Wednesday took place at Foxconn's mammoth industrial park in Shenzhen, which employs 300,000 and where most of the suicides have taken place.

The latest suicide - the 12th this year - occurred on August 4 when a 22-year-old woman jumped from her factory dormitory in eastern Jiangsu province.

Twenty thousand workers dressed in costumes ranging from cheerleader outfits to Victorian dresses filled the stadium at the factory complex, which was decorated with colourful flags bearing messages such as "Treasure your life, love your family."

The workers chanted similar slogans and speakers described their career development at Foxconn.

As they filed toward the stadium for the rally, a flood of workers headed in the other direction to begin the night shift.