About a quarter of the workforce at a chicken processing plant are self-isolating following an outbreak of Covid-19, according to unions.
Representatives from 2 Sisters in Llangefni, Anglesey, say there are 13 confirmed cases among staff, with 110 people self-isolating.
The company has not confirmed the number of cases.
But bosses said the firm was "working to provide the safest possible working environment".
In a statement the company said this was the "key priority".
"We have had a series of measures in place for some time including regular and intensive deep cleaning and disinfecting regimes, the wearing of protective visors in production areas and implementing social distancing throughout the factory," a spokesman said.
Measures were "continually" reviewed, it added.
The company said it had introduced thermal temperature checks and employed marshalls to ensure social distancing was maintained.
Unions have described it as a "major" outbreak. Paddy McNaught, regional officer for Unite, said: "The company are taking this seriously.
"Our stewards are working with the company on site to put protective measures in place.
"But there's no doubt that people are very frightened. They're concerned about bringing the virus home to vulnerable members of their families, and they're concerned about creating a spike in cases on the island."
He said the company and union were pushing for Anglesey council to place a mobile testing unit on the site, so people could be tested more quickly.
2 Sisters Food Group is one of the largest food producers in the UK, with brands including Fox's Biscuits and Holland's Pies.
The company also produces about a third of all the poultry products consumed each day in the UK.
It also has a site in Sandycroft in Flintshire, and says that there are no live cases there at present.
Anglesey council said it was working with Gwynedd council and a number of agencies to advise the company and support staff.
"The North Wales Regional Test, Trace, Protect team is responding to the cluster of coronavirus cases at the 2 Sisters plant in Llangefni as a priority, and supporting the workplace," it added.