BEIJING – Apple’s most important iPhone assembly plant remains in a closed-loop operation that curtails workers’ movement on campus, potentially complicating the effort to resume full production.

Foxconn Technology Group is sticking with measures adopted weeks ago limiting staff movements in order to handle a Covid-19 outbreak, according to a person familiar with operations at the company, who asked not to be named as the information is not public.

The closed-loop approach restricts workers to their dorms or the factory floor, minimising the number of other people they come into contact with in hopes of containing the spread of the virus.

Foxconn, also known as Hon Hai Precision Industry, is keeping up restrictions, even as the local city of Zhengzhou on Tuesday lifted a lockdown of its main urban areas, albeit with an extensive caveat of buildings still considered high risk across the greater region.

Those high-risk areas will remain under lockdown-style controls, and it is not immediately clear whether the Foxconn campus falls among them.

Foxconn’s task of catching up on lost iPhone production time has been complicated by the lockdown, which triggered violent protests last week and pushed thousands of workers to leave the site.

The Taiwanese company has issued several notices announcing bonuses to bring experienced workers back and keep the ones it already has from returning home. BLOOMBERG