Greggs has confirmed an outbreak of coronavirus at its bakery distribution centre in Leeds.
An undisclosed number of people working at the centre in Bramley tested positive.
Following further tests the firm said more staff were found to have the virus and the centre was deep cleaned.
Public Health England could not confirm the exact number of cases but told BBC News it was “less than 20”.
Roger Whiteside, Greggs’ chief executive officer, said the firm had taken immediate action.
He said the company was “working closely with Leeds City Council and Public Health England to ensure that we minimise any possible impact on our customers and the wider community in Leeds and the surrounding area.”
Lucy Jackson, Leeds City Council’s deputy director of public health, said: “Following further testing, more staff have been identified as being positive.
“This highlights why further testing and contact tracing is so important which Greggs is proactively undertaking.
“The workplace is being deep cleaned and further contact tracing carried out, with necessary advice shared about self-isolating and awareness of symptoms.
“We are satisfied the necessary steps are being taken quickly to minimise any further spread of infection.”
“As the virus is still within our community, we should all continue to keep at least two metres away from people outside our households wherever possible, wash our hands with soap and water often, for at least 20 seconds, avoid touching our face and follow the ‘catch it, bin it, kill it’ guidance to help keep ourselves and others safe.