The Taiwan based technology company that supplies Apple products has halted production at one of its plants following a brawl involving as many as 2,000 workers.
Foxconn, which employs around 800,000 workers worldwide, took the decision after four hours of rioting at a plant in Taiyuan, Shanxi province.
Reports claim the riot began following a dispute between a worker at the plant and a security guard.
The row spiralled out of control and escalated as thousands of workers finished their shifts and joined the fighting against the plant's 1,500 security guards.
According to police the fight erupted in a privately managed dormitory near to the factory.
It took four hours for authorities to bring the situation under control.
A police statement reported by the official Xinhua News Agency said 5,000 officers were dispatched to the scene.
The Taiwanese-owned company today declined to say whether the plant was involved in the production of Apple's latest product, the flagship iPhone 5.
The plant, which employs 79,000 workers, is scheduled to reopen today.
Foxconn makes iPhones and iPads for Apple and also assembles products for Microsoft and Hewlett-Packard.
It also produces the Xbox 360, Amazon Kindle, and a range of smartphones from Nokia, Motorola and Sony.
Foxconn's approach to business is often referred to as being that of the 'industrial revolution'.
Workers sleep, live and eat in buildings near to the plants.
The fight in Taiyuan started at 11pm last night, “drawing a large crowd of spectators and triggering chaos”, a police spokesman was quoted by Xinhua as saying.
Comments on Chinese internet bulletin boards suggest the violence was not related to work, and may have begun when a security guard struck a worker.
Photos posted on microblog service Sina Weibo showed broken windows, a burned vehicle and police with riot helmets, shields and clubs.
Foxconn has faced scrutiny in the past over poor working conditions at the factories.
Following a spate of suicides last year the company agreed to reduce hours and improve staff representation.
Despite the criticism, Foxconn is considered one of the better Chinese employers by labour rights groups.
Yesterday's riot follows an incident in June when around 100 workers rioted at a Chengdu plant in south-west China.