Foxconn suffers unrest at iPhone factory Foxconn, the Taiwanese contract manufacturer that makes products for Apple, has been hit by a second bout of labour unrest in less than two weeks as one of its largest factories in China is hurrying to churn out the latest iPhone. More than 200 quality control employees at a Foxconn plant in Zhengzhou, a central Chinese city, refused to work on Friday in protest over their high-pressure work conditions, the company told the Financial Times in an interview on Sunday. Foxconn, the world's largest contract manufacturer by revenue, said large numbers of production line workers had resisted strict qualit y requirements on Friday. Some quality control staff told the FT that they had been threatened by workers. The Zhengzhou plant is one of two Foxconn factories in the country that makes the iPhone5. It employs close to 200,000 workers, according to the company. "The incident was triggered by an emotional standoff between quality control personnel and production line workers," said a Foxconn spokesperson. After we addressed the issues, people on the [Friday] day shift resumed work, and there was basically no impact on the production lines. Since orders for Apple's latest gadget started coming earlier this year, Foxconn has battled chronic labour shortages in manning its massive production lines in China. The Zhengzhou dispute follows a riot at Foxconn's plant in Taiyuan in late September. More than 2,000 workers in the factory - which makes iPhone components - in that northern city smashed shop windows, overturned cars and burnt a police post following a brawl between workers and security guards. On Saturday, Foxconn denied a report by China Labor Watch, a US-based non-governmental organisation, that up to 4,000 of its workers in Zhengzhou went on strike on Friday. It would only acknowledge in a statement that there had been disputes between a small group of production line workers and quality assurance personnel at the Zhengzhou factory earlier in the week on October 1 and 2. In the Saturday statement, Foxconn said: "These were isolated incidents and were immediately addressed and measures taken, including providing additional staff for the lines in question, to address the issues raised by both production workers." But in Zhengzhou, workers, company representatives and government officials told the Financial Times of a continued strain on labour relations that was exacerbated under the pressure caused by the iPhone 5 rush orders. There have been complaints, for example, from consumers about scratches on the back of the new device. "There was some problem with the coating chosen for the casing, so they tightened the rules for quality control," said Cai Yun, an engineer who has been with Foxconn for six years. But the pressure in these jobs is already too high. You add one more thing, and there's bound to be trouble.