An outbreak of Covid-19 cases at a meat processer in northern England owned by British supermarket Asda has caused the plant to close temporarily, Reuters quoted the Walmart-owned retailer as saying on Friday.

Asda said it had been working with public health authorities to ensure staff were tested, and that while the factory in Cleckheaton, West Yorkshire had not been forced to shut, it had been closed as a precaution. It did not confirm how many cases had been found.

"As soon as we became aware that some colleagues at our Kober site may have Covid-19, we responded swiftly and worked collaboratively with the local authority and Public Health England to test all colleagues,” a joint statement by Asda and Kober Limited, the firm which runs the plant, said.

The closure is the latest in a series of outbreaks linked to meat processing plants across Europe and the Americas. On Thursday, one of Britain's biggest food companies suspended production after more than 50 positive tests.