More than 600 workers at a food factory are being tested for coronavirus after 19 colleagues tested positive.
A mobile testing unit has been set up outside Peter’s Food Service unit in Bedwas, Caerphilly.
The pies and pasties maker said it had been “working in a Covid environment for seven months” with safety measures reviewed on a weekly basis.
Caerphilly was the first county in Wales to be placed in a local lockdown following a spike in cases.
A total of 61 more people have just tested positive for coronavirus in the county, according to daily figures published by Public Health Wales on Tuesday.
Peter’s Food Service said as “soon as a colleague informs us that they have received a positive result they are excluded from site and we contact the local authorities to ensure that the track and trace process is implemented”.
It said any employee regarded as a direct contact of a worker who tests positive is “also immediately excluded from site”.
Last week, four staff tested positive and a further six who were excluded have since tested positive for Covid-19.
It said it had also been informed about a further nine cases, of which “we reasonably believe seven are unrelated to any other site case”.
The company said health officials wanted to “understand if there is the potential for onward transmission within the factory environment and determine if Peter’s are likely to see a greater number of cases within the coming week”.
Aneurin Bevan University Health Board, which manages local health services, has been asked to comment.
It has set up a temporary test centre at Senghenydd, Caerphilly, for residents by appointment only, and a “walk-up” test centre at Caerphilly Leisure Centre.
There were outbreaks affecting workers at other food firms at Anglesey, Wrexham and Merthyr Tydfil over the summer.