A Foxconn factory in China, which assembles Apple's iPhones, has shut down for an indeterminate period after about 2,000 workers were involved in a brawl at a dormitory.

The plant was closed Monday and it is not clear how long the shutdown will last.

Foxconn said the trouble started with a personal fight that blew up into a brawl.

But some people said they had heard factory guards had beaten workers, sparking the uproar. These accounts could not be independently verified.

The unrest is the latest in a string of incidents at plants run by Foxconn. The company has faced accusations of poor working conditions and mistreatment of workers at its operations in China, where it employs about 1 million people.

Authorities told Foxconn that about 40 people were taken to hospital and a number were arrested.