Strike hits iPhone production line A customer holds a new iPhone 5 at the Apple Flagship Store on Fifth Avenue as the device goes on sale for the first time on September 21, 2012 in New York City. The new version of Apple's smartphone features a slimmer design, larger screen and a faster web browsing speed. UPI /Monika Graff ZHENGZHOU, China, Oct. 6 (UPI) -- A labor watchdog group in New York said workers had gone on strike at the enormous Foxconn factory in Zhengzhou, China, where the iPhone 5 is made. Apple is one of many major electronics firms that outsource work to the Foxconn factory that was the scene of a riot in September and featured prominently in the news in 2010, after a spate of suicides occurred at the factory. The strike, however, appears centered on quality demands imposed on the workers related to production of the iPhone 5. China Labor Watch in New York said that up to 4,000 production workers at the plant began a strike at 1:00 p.m. Beijing time. Workers were protesting "overly strict demand on product quality without providing worker training for the corresponding skills," said CLW, which describes itself as an independent not-for-profit group that keeps an eye on factory conditions in China. CLW said Saturday that workers were under tremendous pressure to meet quality standards and "could not even turn out iPhones that met the standard." The strike was also prompted by a refusal to grant workers a vacation during a week-long Chinese holiday. CLW also said quality control inspectors joined the strike after fights broke out between inspectors and production workers. After various altercations between the two groups management "turned their backs on the issue," CLW said in a statement. "This strike is a result of the fact that these workers just have too much pressure," said CLW Executive Director Li Qiang.