A second locally acquired case of COVID-19 has sent Perth and the Peel region in Western Australia into lockdown.
A man aged in his 30s who is thought to have contracted the virus at the Indian Ocean Brewery is the latest case, with Premier Mark McGowan taking no chances.
"We're hopeful a four-day lockdown and all of the measures we're putting in place will be enough to crush and kill the virus in its tracks," he told reporters of the stay-at-home order which came into effect at midnight.
The man dined at the brewery last Tuesday, eating at a different table to a woman who returned from Sydney and subsequently tested positive to the Delta variant of the virus.
"What is even more concerning is this most recent infection appears to have involved only fleeting contact with the original case," Mr McGowan said.
Another woman, aged 32, also tested positive after coming into contact with the original case.
"We know there are two cases of community spread of the virus from the woman who went to Sydney," the premier said.
"We don't know how many more people have acquired it via this technique. That's why we're engaging in the measures which are pretty strong."
Everyone from the brewery that night is in isolation, he added.
"This gentleman who has acquired it ... has been in the community. We don't know where he's been. We don't have his contacts. We do know some of these locations."
Compulsory face masks outside the home will accompany the lockdown, during which people are directed not to leave their residence except for essential reasons.
Schools and childcare centres will remain open.
"People who have to go to work, they often need kids to go to school because they don't have alternatives," Mr McGowan said.
The premier refused to enter a "blame game" over the origin of the Perth infections.
"It will be easy for me to point the finger and say 'it's all their fault'," he said.
"What's happened has happened. We can't control it. We just need to do our best to manage it.
"And make sure that we get through this safely, swiftly and in a very healthy way."
The WA branch of the AMA earlier on Monday called for a lockdown of two to three days to give contact tracers time to get on top of the situation.
"We have significant fears that because it's the Delta variant, and that we've seen this already occur in NSW ... that it's actually gotten away from the contact tracers," president Mark Duncan-Smith said.
WA has deemed Queensland, the Northern Territory and the ACT to be jurisdictions of low risk, meaning arrivals must get tested and self-isolate for 14 days.
A hard border was earlier reimposed for NSW residents.
