Perth and the South West entered a five-day lockdown last night after a hotel quarantine security guard tested positive to the highly infectious UK strain of COVID-19.

The two drive-through screening facilities, in Wangara and at Perth Airport, were established by MinRes in April 2020.

MinRes said it was taking all precautions to keep its people safe and operations running.

While all sites are operating as normal, movement of workers has been minimised in line with a request from the WA government.

Only essential workers will mobilise to site and all workers going to site will be screened and must return a negative result prior to mobilisation.

Following the screening, the worker will be instructed to remain in strict isolation at home post-screening and before they fly out to site. If there is a positive result for COVID-19, the worker will not fly out to site and the Department of Health will be alerted and take over the case management.

"The health and wellbeing of our workforce and the safety of our community is our priority focus and we are doing everything possible to support the McGowan government to limit the spread of COVID-19," MinRes managing director Chris Ellison said.

"The state government has been very clear on their desire to keep the state's mining industry open for business.

"Mineral Resources, as a key player of this essential industry and employing nearly 4000 men and women, is committed to assisting the government in this latest outbreak by offering our world-class facilities to the community to help take pressure off the government screening facilities."

"We are fortunate to have been able to secure certified testing machines and the necessary testing kits to help Western Australia's fight against COVID-19 and will do everything we can to help minimise the spread of the virus."

Red 5 said today its Eastern Goldfields operations remained unaffected, while fellow gold miner Westgold Resources said there has been only a minimal impact.

Gascoyne Resources said it did not expect a material impact, but was implementing roster changes for employees and contractors.

It follows updates from Northern Star Resources and Saracen Mineral Holdings this morning, which also said operations were unaffected.