One factor behind the unrest is that workers found out they would not receive higher wages they had been promised unless they stayed at the factory through March. The 10,000 yuan payment would compensate people unhappy with that restriction for their travel back home.

Mounting dissatisfaction among Foxconn’s ranks threatens to further disrupt production at a plant that cranks out the majority of Apple’s marquee devices for shipment around the world. The US company has already warned it will ship fewer devices than anticipated during the critical holiday quarter, while wait times for iPhones have ballooned in some cases to after Christmas.

“We have Apple team members on the ground at our supplier Foxconn’s Zhengzhou facility,” the US company said in a statement. “We are reviewing the situation and working closely with Foxconn to ensure their employees’ concerns are addressed.”

Workers streamed out of dormitories in the early hours of Wednesday, jostling and pushing past the white-clad guards they vastly outnumbered. Several white-suited people pummeled a person lying on the ground with sticks in another clip. Onlookers yelled “fight, fight!” as throngs of people forced their way past barricades. At one point, several surrounded an occupied police car and began rocking the vehicle while screaming incoherently.

The protest started over unpaid wages and fears of spreading infection. Several workers were injured and anti-riot police arrived on the scene to restore order.

The plant had resumed normal operations by Wednesday evening, Foxconn said in a statement. But the protests underscored how Mr Xi’s policy, which relies on swift lockdowns to stamp out the disease wherever it pops up, is increasingly weighing on the economy and throwing swathes of the global supply chain into disarray.

The Foxconn situation serves up another reminder of the dangers for Apple of relying on a vast production machine centred on China at a time of unpredictable policy and uncertain trade relations.

Beijing recently issued new directives ordering officials to minimise disruption and use more targeted COVID-19 controls, but surging outbreaks in major cities have forced local authorities to reach for strict curbs again.

Hours after the Zhengzhou violence, the local government announced “mobility controls” over parts of the city through to November 29 – an effective lockdown that could hamper efforts to recruit new workers to replace those who leave.

“Media reports indicate the protests were not outside the production facilities,” Morgan Stanley analysts wrote. “Hence, we expect production operations should be able to continue. The company maintains a target of full operation at its Zhengzhou Park by the end of November.”

Bloomberg