BEIJING - Employees at the world's biggest Apple iPhone factory were beaten and detained in protests over pay amid anti-virus controls, according to witnesses and videos on social media Wednesday, as tensions mount over Chinese efforts to combat a renewed rise in infections.

Videos that said they were filmed at the factory in the central city of Zhengzhou showed thousands of people in masks facing rows of police in white protective suits with plastic riot shields. Police kicked and hit a protester with clubs after he grabbed a metal pole that had been used to strike him.

Frustration with restrictions in areas throughout China that have closed shops and offices and confined millions of people to their homes has boiled over into protests. Videos on social media show residents tearing down barricades set up to enforce neighborhood closures.

The ruling Communist Party promised this month to try to reduce disruptions by shortening quarantines and making other changes. But the party is sticking to a 'zero-COVID' strategy that aims to isolate every case while other governments relax controls and try to live with the virus.

Last month, thousands of employees walked out of the iPhone factory operated by Taiwan's Foxconn Technology Group over complaints about unsafe working conditions following virus cases.

A protest erupted Tuesday over complaints Foxconn changed conditions for new workers who were attracted by offers of higher pay, according to Li Sanshan, an employee.

Li said he quit a catering job in response to advertising that promised 25,000 yuan ($3,500) for two months of work. Li, 28, said workers were angry after being told they had to work two additional months at lower pay to receive the 25,000 yuan.

'Foxconn released very tempting recruiting offers, and workers from all parts of the country came, only to find they were being made fools of,' Li said.

Foxconn, headquartered in New Taipei City, Taiwan, said in a statement the 'work allowance' has 'always been fulfilled based on contractual obligation.'

Foxconn denied what it said were comments online that employees with the virus lived in dormitories at the Zhengzhou factory. It said facilities were disinfected and passed government checks before employees moved in.

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

Protests have flared as the number and severity of outbreaks has risen across China, prompting authorities in areas including Beijing, the capital, to close neighborhoods and impose other restrictions that residents say go beyond what the national government allows.

More than 253,000 cases have been found in the past three weeks and the daily average is increasing, the government reported Tuesday. This week, authorities reported China's first COVID-19 deaths in six months.

On Wednesday, the government reported 28,883 cases found over the past 24 hours, including 26,242 with no symptoms. Henan province, where Zhengzhou is the capital, reported 851 in total.

The government will enforce its anti-COVID policy while 'resolutely overcoming the mindset of paralysis and laxity,' said a spokesman for the National Health Commission, Mi Feng.

The city government of Guangzhou, the site of the biggest outbreaks, announced it opened 19 temporary hospitals with a total of almost 70,000 beds for coronavirus patients. The city announced plans last week to build hospital and quarantine facilities for 250,000 people.

Also Wednesday, Beijing opened a hospital in an exhibition center and suspended access to Beijing International Studies University was suspended after a virus case was found there. The capital earlier closed shopping malls and office buildings and suspended access to some apartment compounds.

Foxconn said earlier its Zhengzhou factory uses 'closed-loop management,' which means employees live at their workplace with no outside contact.

The protest lasted through Wednesday morning as thousands of workers gathered outside dormitories and confronted factory security workers, according to Li.

Other videos showed protesters spraying fire extinguishers toward police.

A man who identified himself as the Communist Party secretary in charge of community services was shown in a video posted on the Sina Weibo social media platform urging protesters to withdraw. He assured them their demands would be met.

Apple Inc. has warned deliveries of its new iPhone 14 model would be delayed due to anti-disease controls at the factory. The city government suspended access to an industrial zone that surrounds the factory, which Foxconn has said employs 200,000 people.

News reports said the ruling party had ordered 'grassroots cadres' to fill in for Foxconn employees in Zhengzhou who left. The company didn't respond to requests for confirmation and details about that arrangement.