Lockdown to end but restrictions to continue: Premier

From 12.01am Tuesday until 12.01am Saturday interim restrictions will apply, Mark McGowan said in a press conference on Monday afternoon.

People will be free to leave homes but masks will remain mandatory. Masks are not required for primary school children, vigorous exercise and people who are exempt.

People can return to work unless they can return from home or in vulnerable category.

Schools will return tomorrow but staff and secondary students will be required to wear masks.

"There will be a 20-person limit on homes and gatherings," the premier said. "Entertainment and hospitality venues can reopen except for casinos and gyms. The 4sqm rule will apply and sit-down service only will apply."

For next four days, wedding and funerals can apply for an exemption to have more than 100 visitors.

Community sport can proceed but without visitors.

Travel into regions are permitted but masks required. Anyone in another region who has been in Perth and the Peel since April 17 will be required to wear a mask.

Mr McGowan said the lockdown was "the circuit breaker we needed".

Since Friday, 29,963 tests have been completed in WA.

Currently there are 748 casual contacts identified of the three people who contracted the virus in WA, and more than half test results have been returned, all negative so far.

"I wish we didn't have to go into lockdown but it's been necessary and it worked," Mr McGowan said.

"We can't go back to where we were last week just yet."

Australia has recorded no new community COVID-19 cases in the past 24 hours as West Australians wait to learn whether they will be freed from lockdown.

Federal Health Minister Greg Hunt confirmed the news ahead of Premier Mark McGowan's media conference scheduled for 12.30 local time.

Perth and the Peel region are due to emerge from the three-day lockdown at midnight but the premier has flagged that some restrictions will remain.

Two locally-acquired cases have been confirmed after the virus leaked out of the Mercure quarantine hotel last week.

Authorities were on Sunday still waiting to clear more than 270 close and casual contacts of the local cases, some of whom had not yet been tested.

The guest at the Mercure whose infection led to the outbreak had travelled to India last December to attend his own wedding.

Both he and his bride tested positive in hotel quarantine upon returning to Australia earlier this month.

Genomic testing has confirmed the virus spread from the couple to several other guests in nearby rooms, including a Melbourne man who did not test positive until after he had completed quarantine and spent five days in the community.

Home Affairs Minister Karen Andrews defended the wedding travel exemption amid a growing war of words between the state and federal governments.

"When the exemption was granted for that individual it was absolutely in line with the criteria at the time," she told Perth radio 6PR on Monday.

"What we have done since that time is tighten it in terms of the criteria and the reasons for travel ... a wedding would (now) be unlikely to be approved."

Ms Andrews said travel was now only permitted to India if it was in the national interest, part of the COVID response or for medical treatment unavailable in Australia.

A female friend of the Melbourne man also tested positive after he stayed at her house upon leaving quarantine.

On Saturday, a second locally-acquired case was detected - a man in his 40s who had dined at the same Kardinya restaurant as the Melbourne man.

His household contacts have been cleared of the virus, but authorities have extended the list of possible transmission sites, including a childcare centre, based on his recent activities.

The premier was expecting more than 12,000 COVID tests to be completed on Sunday.

"We'll get health advice...and I think people should get used to the prospect that there will be some further measures continue beyond Monday," he said.

Mr McGowan has criticised the federal government for not providing better quarantine facilities, saying CBD hotels are not suitable.

He wants Canberra to open air bases and Christmas Island to accommodate travellers, adding that it is the Commonwealth's constitutional responsibility to handle the quarantine scheme.

Ms Andrews said the facilities were not fit for purpose and the WA premier should focus on finding constructive solutions.

"The tit-for-tat politics is not helping Australians and it really just needs to stop," she said.