China suspended poultry imports from a Tyson Foods Inc. plant where hundreds of employees tested positive for Covid-19, stoking concerns over the broader implications for U.S. and global meat exports.

All products from the plant in Springdale, Arkansas, where Tyson is based, that are about to arrive in China or have arrived at the country’s ports will be seized by customs. The suspension announced Sunday is an about face from just a few days ago, when Chinese officials said food was unlikely to be responsible for a fresh virus outbreak in Beijing.

The move is a potential new threat to meat plants across the world that have seen slaughter disruptions because of the virus. In the U.S., hundreds of workers have become ill, and dozens have died. There’s also been a recent uptick in infections at facilities in Brazil and Germany. “There are worries in China over serious coronavirus outbreaks in the U.S.,” said Lin Guofa, a senior analyst at Bric Agriculture Group, a Beijing-based consulting firm. The public is worried about imported frozen products as almost all cases in Beijing have been connected to a meat and frozen fish wholesale market, he said. A new outbreak in China had been blamed on imported salmon after the head of a food market where clusters were detected said the virus had been traced to a chopping board used by a fish seller. Fears over whether food can transmit viruses had led salmon to be boycotted in the Asian country.