Beijing: Violent worker protests erupted at the world's largest iPhone factory in central China as authorities at the Foxconn plant struggle to contain a COVID-19 outbreak while maintaining production ahead of the peak holiday season.

On Thursday morning, some workers who had agreed to leave had received the first part of the payment, a worker said in a live stream, which showed workers lining up outdoors to take Covid tests while they waited for departing buses. Later in the day, live streams showed long lines of workers boarding buses.

But for some, the trouble is far from over. After being driven to the Zhengzhou train station, many couldn't get a ticket home, another worker said in a live stream on Thursday afternoon. Like him, thousands of workers were stuck at the station, he said, as he turned his camera to show the large crowds, reported CNN.

Zhengzhou is set to impose a five-day lockdown in its urban districts, which include the train station, starting from midnight Friday, authorities had announced earlier.

After Foxconn announced it would pay 10,000 yuan per employee as a resignation subsidy to calm the situation, on November 25, it was reported that the departing employees were trapped at the train station and clashed with the police again.

The troubles started last month when workers left the factory campus in Zhengzhou, the capital of the central province of Henan, due to Covid fears. Short on staff, bonuses were offered to workers to return, reported CNN.

Clashes with the police were seen at an isolation site in Tongxu County, Kaifeng, Henan. Employees of Foxconn in Kaifeng's Weishi quarantine hotel took to the streets and clashed with the police.

Workers tried to enter the government building leading to a confrontation with the police.

Workers at the factory in Zhengzhou shared more than a dozen videos that show staff in a standoff with lines of police armed with batons and clad in white protective gear. The videos show police beating workers, with some bleeding from their heads and others limping away from chaotic clashes, reported CNN.

According to a document setting out the salary package of new hires seen by CNN, the workers were promised a 3,000 yuan bonus after 30 days on the job, with another 3,000 yuan to be paid after a total of 60 days.

However, according to a worker, after arriving at the plant, the new recruits were told by Foxconn that they would only receive the first bonus on March 15, and the second instalment in May - meaning they must work through the Lunar New Year holiday, which starts in January 2023, to get the first of the bonus payments.

"The new recruits had to work more days to get the bonus they were promised, so they felt cheated," the worker told CNN.

In a statement Thursday, Foxconn said it fully understood the new recruits' concerns about "possible changes in the subsidy policy," which it blamed on "a technical error (that) occurred during the onboarding process."

"We apologize for an input error in the computer system and guarantee that the actual pay is the same as agreed," it said.

Foxconn was communicating with employees and assuring them that salaries and bonuses would be paid "in accordance with company policies," it said.

Apple, for which Foxconn manufactures a range of products, told CNN Business that its employees were on the ground at the Zhengzhou facility.

"We are reviewing the situation and working closely with Foxconn to ensure their employees' concerns are addressed," it said in a statement.

Wednesday's unrest will heighten investor concerns about supply chain risk at Apple, with more than 95 per cent of iPhones produced in China.

Problems at the plant earlier this month led Apple to cut estimates for high-end iPhone 14 shipments and to issue a rare warning to investors over the delays.

China is further scrambling Apple's strained supply and highlighting how the country's stringent zero-Covid policy is hurting global technology firms.

Analysts said the woes facing Taiwan contract manufacturing firm Foxconn, a top Apple supplier which owns the facility, will also speed up the pace of diversification away from China to countries like India.

Daniel Ives, managing director of equity research at Wedbush Securities, told CNN Business that the ongoing production shutdown in Foxconn's sprawling campus in the central Chinese city of Zhengzhou was an "albatross" for Apple.

"Every week of this shutdown and unrest we estimate is costing Apple roughly USD 1 billion a week in lost iPhone sales. Now roughly 5 per cent of iPhone 14 sales are likely off the table due to these brutal shutdowns in China," he said.

Demand for iPhone 14 units during the Black Friday holiday weekend was much higher than supply and could cause major shortages leading into Christmas, Ives said, adding that the disruptions at Foxconn, which started in October, have been a major "gut punch" to Apple this quarter.

In a note Friday, Ives said Black Friday store checks show major iPhone shortages across the board.

Notably, the protest against the zero-Covid policy of China escalated after 10 people died inside their apartments in the fire in Urumqi, Xinjiang Province on November 24. The fire started around 7:49 pm.

Fire trucks were delayed by lockdown barricades. 10 residents locked down inside their homes were killed, and another 9 rushed to hospital.

There were over 1.5 billion views on Weibo on the related hashtag but it was not in the trending list, hence one could find it only if it appears in the feed or searches for it.

Chang Che, a freelance writer covering Chinese technology and society and Amy Chang Chien covering news in mainland China and Taiwan, writing in The New York Post (NYT) said that the protest erupted after the fire killed 10 persons in the region, with residents calling for the lifting of lockdowns that have confined many to their homes for more than three months.

On November 25, residents of several communities in Urumqi, Xinjiang protested demanding the unblocking of the neighbourhood. As a result, the authorities dispatched many police officers to suppress the incident, including even armoured vehicles.

It was reported that the collective protest of the residents was triggered by the beating of a resident, but the essence was that the residents who had been locked up for more than 3 months had reached the limit of their patience, so they vented out their dissatisfaction and expressed their demands for the release of the blockade.

The residents shouted "unblock unblock" and nearby localities also protested demanding unblocking. Meanwhile, the authorities beefed up security to quell the protests.

Late Friday, videos circulated widely on the Chinese internet showing throngs of residents in Urumqi marching to a government building and chanting "end lockdowns," the latest sign of mounting frustration with Beijing's exceptionally stringent pandemic measures, reported Chang and Amy.

Many of the videos were later removed from China's heavily censored social media platforms.

The fire was ignited by a power strip that caught fire in a bedroom on the 15th floor of a residential building in Urumqi on Thursday evening, the city's Fire Department said. It later rose to engulf the two floors above, the department said.

Much of Xinjiang, a region of 25 million people, has been under lockdown for more than 100 days as part of the authorities' heavy-handed response to Covid outbreaks.

In some cases, the lockdowns have left residents in dire straits, with trouble securing food and other necessities, like medication and menstruation supplies, reported New York Times.