Western Australia will consider implementing a hard border to control its coronavirus infection rates, with non-locals urged to stay away.
Thirty-three new cases have been confirmed, taking the state's total to 311.
Most of the state's confirmed cases have been travellers from overseas or passengers on cruise ships that docked in the eastern states.
Non-West Australians are currently allowed to travel to WA providing they go into isolation for 14 days upon arrival.
However, Premier Mark McGowan is considering denying entry to anyone other than essential workers or returning WA residents.
"A clear message to people over east: if you're not a West Australian and you want to come to Western Australia, don't come," Mr McGowan said on Sunday.
"We don't want you here."
WA's infection growth rate has been relatively low compared with NSW, where the majority of Australia's cases have been recorded.
Health Minister Roger Cook said three-quarters of WA's confirmed cases had either come from a flight or a cruise ship.
"In Western Australia, our problem isn't community spread, our problem is people returning to the state," he said.
Residents will nonethless continue to be watched closely.
A dedicated police squad with more than 200 officers will patrol WA's streets to ensure people adhere to coronavirus restrictions.
The state government will introduce legislation for $1000 on-the-spot fines for individuals and $5000 for businesses that do not comply.
Authorities will also shut down popular beaches such as Cottesloe and Scarborough if social distancing requirements are not met.
WA's health department on Sunday also announced the temporary closure of the state's 15 breast screening clinics to protect clients and staff.
Hundreds of healthy cruise ship passengers have begun flying out of Perth as dozens more wait for coronavirus test results.
Up to 55 passengers and crew from the German liner Artania in Fremantle are suspected to be infected and will be treated at private hospitals across Perth.
About 800 healthy passengers and some crew are being flown back to Germany on Sunday.
New Zealanders on board the Vasco da Gama cruise ship also flew home overnight. About 200 passengers from WA will be ferried to Rottnest Island on Monday to go into isolation for 14 days.
A further 600 Australians will be quarantined at the Duxton Hotel in Perth's CBD for two weeks before flying home.
The same arrangement will be in place for a Qatar Airways aircraft due to land in Perth on Monday carrying Australian passengers from Italian cruise liners.
About 270 Australians are on board the flight, including 120 West Australians.
No passengers with coronavirus symptoms were allowed to board, the premier said.
Two people linked to cruise ships have died in WA from the virus.
Australian Associated Press