Seafood plants in Zhuanghe, the main processing district in the northeast port city of Dalian in China, have been shuttered due to a new wave of COVID-19, and will only reopen once cases fall to zero, IntraFish has learned.

Authorities in the city moved to suspend production at the plants following an outbreak of cases.

In one instance, 20 positive cases were reported at a seafood plant, leading to all the plants in Zhuanghe being shut down.

More than 1,000 cases have been reported during China’s latest current coronavirus wave, forcing the cancellation of marathon races in Shanghai Wuhan, Shijiazhuang and the capital city of Beijing, the South China Morning Post reported.