A riot broke out at a Foxconn factory in China, involving 2,000 workers at one of Apple’s principal suppliers. The factory is used in the manufature of Apple's latest iPhone 5. Watch: iPhone 5 video review

Foxconn confirmed that 40 workers were injured and many arrested in a "personal dispute" that escalated into a major four-hour mass brawl. The factory was closed as a result of the distrurbance.

Police were called to the factory in Taiyuan, northern China, which employs about 79,000 workers.

Update: The riot appears to have kicked off after workers from Foxconn's other manufacturing facilities in China were transferred to the Taiyuan facility to learn how to assemble Apple’s iPhone 5, reviewed. These new transfers are apparently less tolerant of Foxconn's security guards, who are alleged to be aggressive to assembly-line workers.

Reports on social media suggested that the injuries may have been caused when people were trampled in “crowds of protesters,” reported The New York Times.

Apple has previously been caught up in Foxconn controversy, with widespread reports of its poor working conditions leading to suicides among staff.

The violent incident started on Sunday at about 11pm local time in a workers dormitory near the Taiyuan manufacturing facility in Shanxi province, reports the BBC.

Photographs (see above) and video circulated on social networking sites apparently showed smashed windows and riot police at the factory.

The plant makes electronic components for consumer devices and cars. The Taiwanese company also counts Sony, Microsoft and Nintendo as customers.