Western Australia will close three “high-risk” quarantine hotels and indefinitely reduce its returned traveller intake after the COVID-19 breach that prompted this week’s snap lockdown.

Premier Mark McGowan said the Mercure, Sheraton Four Points and Novotel Langley would stop taking guests from as early as mid-May.

“Whilst they are very secure, obviously they’re not perfect and the ventilation systems there we can’t make perfect. So we’re going to move out of those,” he said on Wednesday.

“That will result in a reduction in the number of people we can take into Western Australia. We’ll work out what that is and how many we can take.”

Two locally acquired infections were found after the virus leaked out of the Mercure hotel, plunging Perth and the Peel region into a long-weekend lockdown.

It has since emerged the government was aware of ventilation issues at the Mercure and two other “high risk” quarantine hotels.

WA had its third straight day without new local cases on Wednesday.

It had four in hotel quarantine, including “one or two” in people returning from India. Mr McGowan said India was generally accounting for half of the COVID infections in returned Australian travellers.

“It’s terribly tragic … They’re basically cutting down trees in parks to provide enough wood for cremations because so many people are dying. It’s awful,” he said.

“But as we’ve seen over the course of the last week, it puts a lot of pressure on our system so we’re doing all we can to make sure that Australia and Western Australia remain in the very good condition we are and that means we have to make difficult and tough decisions.”

Queensland and NSW each had nine more overseas acquired infections, while Victoria had two.

Mr McGowan said he had advised Prime Minister Scott Morrison of the decision to retire the quarantine hotels.

“The Prime Minister was right when he said yesterday that our hotel quarantine system has been 99.99 per cent secure,” he said.

“The problem with that 0.01 per cent is that the consequences can be dire. So that’s why we’re going to do everything we can to make sure we are as secure as possible in Western Australia.”

Mr McGowan added that WA had been taking the highest number of returned travellers as a proportion of its population.

WA’s cap on international arrivals has been halved to 512 a week for the next month.

The decision to close three hotels will make it seemingly impossible for the cap to return to its previous level of 1025 a week.

It will leave WA with seven quarantine hotels, with the Adnate in West Perth set to start accommodating international travellers.

Mr McGowan said the Novotel would accommodate a flightload of “low-risk” seasonal workers from Tonga and Vanuatu in May.

The Sheraton Four Points was the site of a breach involving a security guard which led to an earlier lockdown in January.

-with AAP