Workers at the world’s largest iPhone factory clashed with police after protests broke out at the Foxconn factory in the Chinese city of Zhengzhou, reports The Wall Street Journal. This huge enterprise, which employs more than 200,000 people, has been under strict control for several weeks due to Covid-19.

Videos circulating on employee work chats showed chaotic scenes at the Zhengzhou factory where technology group Foxconn assembles most of the latest iPhone models. One video, taken near the factory buildings on the northeast side of the site, shows more than a dozen police officers and people in white protective suits surrounding and repeatedly hitting the man with fists and batons.

Workers at the plant said the protests began in a dormitory area near the plant on Tuesday night after they learned that expected bonuses would be delayed. The protests spread to at least one other sleeping area when video footage of the incident went viral, workers said. Workers tore down tents that had been set up outside, and the building’s glass front door was broken, as seen in the video.

In a statement on Wednesday, Foxconn confirmed that the violence was related to concerns among some new workers about their wages. The company said it had always met its contractual obligations regarding pay and would communicate with workers and the government to prevent the incident from happening again. The police responsible for the area declined to comment.

One Foxconn recruit said that as of around noon Wednesday, he had seen no attempt by the company to take control of the situation in the face of the angry mob. “There is practically no security in the factory campus,” he said.

Apple did not respond to requests for comment on the protests, but the company said last month that shipments of new iPhone models would be lower than expected due to production disruptions. According to Counterpoint Research, Foxconn’s Zhengzhou plant was expected to produce more than 80% of the latest iPhone 14 base models and 85% of the high-end Pro models.

Apple recently told suppliers to plan more aggressively to increase production outside of China, citing the country’s strict pandemic measures, among other reasons.

The chaos in Zhengzhou is the result of a desire to meet Apple’s production needs, said Li Qiang, a spokesman for China Labor Watch. According to him, Apple employees work at the factory, and they should not blame their suppliers for the conditions there.

Foxconn is offering bonuses to new employees this month as it seeks to reopen after tens of thousands of workers were quarantined or locked in their dormitories as part of China’s Covid Zero policy. But as Foxconn tightened campus restrictions to keep assembly lines running, thousands more workers fled for fear of catching the disease and amid rumors that infected people were being allowed to work so the company could carry out its plans.