A labour watch group says thousands of workers at a Chinese factory that makes parts for Apple’s iPhone 5 have gone on strike.

China Labour Watch says as many as 4,000 workers at the Fox-Conn Zheng-Zhou factory have gone on strike over increased quality-control demands, as well as having to work during an extended national holiday.

Several production lines have reportedly been halted by the strike, with the workers saying the new demands are too difficult to meet.

The watchdog group says workers beat quality-control inspectors, who also carried out a work stoppage after management ignored their complaints.

The company has had plenty of labour trouble recently. Just last month 2,000 workers were involved in a brawl at another factory.

Foxx-Conn has denied the reports, saying production is continuing without interruption.