ZHENGZHOU: Hundreds of workers joined protests at Foxconn's (2317.TW) flagship iPhone plant in Zhengzhou China, with some men smashing surveillance cameras and windows, footage uploaded on social media showed.

The rare scenes of open dissent in China mark an escalation of unrest at the massive factory in Zhengzhou city that has come to symbolise a dangerous build-up in frustration with the country's ultra-severe Covid-19 rules as well as inept handling of the situation by the world's largest contract manufacturer.

The trigger for the protests, which began early on Wednesday, appeared to be a plan to delay bonus payments, many of the demonstrators said on live stream feeds. The videos could not be immediately verified by Reuters.

“Thank you for speaking up for Chinese people!”

Apple restricted AirDrop on China mainland devices in iOS 16 because people used AirDrop to spread protest messages. The update is seen as Apple's compromise to the Chinese authorities. Someone twittered on their Twitter account.

"F**k you, Communist Party" one Foxconn worker yells

"Give us our pay!” chanted other workers surrounded by people in full hazmat suits, some carrying batons, according to footage from one video. Other footage showed tear gas being deployed and workers taking down quarantine barriers. Some workers had complained they were forced to share dormitories with colleagues who had tested positive for Covid-19.

In the videos, workers vented about how they were never sure if they would get meals while in quarantine or over inadequate curbs to contain an outbreak.

"Foxconn never treats humans as humans," said one person.

"It's now evident that closed-loop production in Foxconn only helps in preventing Covid from spreading to the city, but does nothing (if not make it even worse) for the workers in the factory," Aiden Chau of China Labour Bulletin, a Hong Kong-based advocacy group, said in an email.

As of Wednesday afternoon, most of the footage on Kuaishou, a social media platform where Reuters reviewed many of the videos, had been taken down. Kuaishou did not respond to a request for comment.

A source familiar with the situation in Zhengzhou said production at the plant was unaffected by the worker unrest and output remained "normal".

Foxconn, formally called Hon Hai Precision Industry Co Ltd, said in a statement it had fulfilled its payment contracts and that reports of infected staff living on campus with new recruits were "untrue."

"Regarding any violence, the company will continue to communicate with employees and the government to prevent similar incidents from happening again," the company added.

Foxconn accounts for 70% of iPhone shipments globally. It makes most of the phones at the Zhengzhou plant.

Apple did not respond to requests for comment.