Around 4,000 Foxconn workers struck at the end of last week in the central Chinese city of Zhengzhou.
Foxconn manufactures the iPhone and other pricey electronics. The Zhengzhou factory is one of two plants in China where it makes the Apple gadgets.
The strike was over management bullying and workers being made to do compulsory overtime. Workers rioted at two other Foxconn plants recently, triggered by fights with security guards.
In Taiyuan up to 2,000 workers smashed windows and forced the plant to close for days. Other complaints include poor food, sanitation and overcrowding.
Foxconn’s workers are usually young, educated migrants from within China. The jobs are highly sought after as the pay is above average for the country.
The plants previously hit the headlines after a wave of suicides among the workers. It highlighted the misery of their working conditions and expensive crowded dormitories.