China is telling food companies and retailers in Beijing not to accept any shipments of frozen food from countries wher the coronavirus has been detected in previous shipments.

A statement from the Beijing Municipal Commerce Bureau warns that “customs and local authorities have repeatedly detected the [coronavirus] in imported cold chain foods, proving that imported cold chain foods are indeed at risk of contamination.” It tells food importers to “take the initiative to avoid importing cold chain food from areas with severe epidemics” and look for alternatives.

The statement comes after China declared that it had found SARS-CoV-19, the virus that causes COVID-19, in frozen poultry and seafood. China has already suspended imports from dozens of food companies in at least 19 countries, including Tyson Foods, CNN reports.

The attitude of the Chinese government goes against the advice of bodies like the World Health Organization, which say the primary mode of transmission for the coronavirus is airborne and that there is no evidence of a risk from food or its packaging.