Cities in central China rapidly devised plans to segregate migrant workers escaping to their hometowns from a massive Foxconn assembly plant in COVID-stricken Zhengzhou out of concern that they would start coronavirus outbreaks.

The number of locally transmitted COVID-19 cases reported in Zhengzhou, the provincial capital of central Henan, increased from 97 to 167 in the seven days leading up to October 29.

Apple supplier Foxconn, based in Taiwan, currently has about 200,000 workers at its Zhengzhou complex and has not disclosed the number of infected workers, but said on Sunday that it would not stop workers from leaving.

Late on Saturday, cities near Zhengzhou, including Yuzhou, Changge and Qinyang, urged Foxconn workers to report to local authorities in advance before heading home.

Returning workers are to travel “point-to-point” in pre-arranged vehicles and are to be quarantined on arrival, they said in separate letters on their respective social media accounts addressed to Zhengzhou Foxconn workers.