The company that assembles Apple's iPhones in China has apologised for what it called a technical error that led to protests by employees over wages offered to attract them to a factory currently under coronavirus restrictions.
Protests erupted on Tuesday in the central city of Zhengzhou after employees complained Foxconn Technology Group required them to carry out extra work in order to receive the higher pay they were promised by recruiters.
Foxconn is trying to rebuild its workforce after thousands of employees walked out last month over complaints about unsafe conditions.
Videos on social media showed police in white protective suits kicking and clubbing workers as they protested.
Foxconn, the biggest contract assembler of smartphones for Apple and other global brands, blamed the dispute on a "technical error" in the process of adding new employees. It promised they would receive the wages they were promised.
"We apologise for an input error in the computer system and guarantee that the actual pay is the same as agreed and the official recruitment posters," the firm said.
It promised to "try its best to actively solve the concerns and reasonable demands of employees".
The dispute comes as the ruling Communist Party tries to contain a surge in coronavirus cases without shutting down factories, as it did in 2020 at the start of the pandemic.
Its tactics include "closed-loop management", meaning employees live at their workplaces without outside contact.
Despite that, the infection surge has prompted authorities to suspend access to neighbourhoods and factories and to close office buildings, shops and restaurants in parts of many cities.
Apple earlier warned iPhone 14 deliveries would be delayed after employees walked out of the Zhengzhou factory and access to the industrial zone around the facility was suspended following outbreaks.
To attract new workers, Foxconn offered 25,000 yuan ($A5200) for two months of work, according to employees, or almost 50 per cent more than news reports say its highest wages usually are.
Employees complained that after they arrived, they were told they had to work an additional two months at lower pay to received the higher wage.
Foxconn offered up to 10,000 yuan to new hires who chose to leave, finance news outlet Cailianshe reported.
Foxconn on Thursday said employees who left would receive unspecified "care subsidies" and promised "comprehensive support" for those who stayed.