The Zhengzhou Airport Economy Zone in central China said it would impose "silent management" measures with immediate effect including barring all residents from going out and only allowing approved vehicles no the roads. The curbs will stay in place until Nov. 9, it said.
Foxconn, formally Hon Hai Precision Industry Co Ltd, is Apple's biggest iPhone maker, producing 70% of iPhone shipments globally. It makes most of the phones at the Zhengzhou plant where it employs about 200,000 people, though it has other smaller production sites in India and south China.
The industrial park's notice did not specify how the measures might be applied to Foxconn. Foxconn and Apple did not immediately respond to a request for comment.
Foxconn has been working to retain staff and smooth over tensions in the factory, after workers complained about their treatment and provisions under Covid-19 prevention measures. Several employees also fled the factory, prompting Foxconn to offer generous bonuses to retain staff.
The park also locked down earlier this year in late April for 14 days. Foxconn said at the time that its production at the plant was normal.
Wednesday's lockdown marks a re-tightening of measures in Zhengzhou, which unexpectedly lifted a quasi-lockdown on its nearly 13 million people the day before. The city reported 358 locally transmitted cases for Tuesday, up from 95 the day before.