More than 640 COVID-19 cases are linked to the Sioux Falls plant of the meat packing giant Smithfield Foods in South Dakota, The New York Times reported on Wednesday.

The Sioux Falls plant with a total of 3,700 employees is now the largest single-source of cases in the U.S., said the report.

Smithfield Foods announced on Wednesday the closure of two more meat processing plants in Missouri and Wisconsin after a massive coronavirus outbreak closed the South Dakota factory.