The acting chief medical officer has thrown his support behind the Victorian authorities for the actions they have taken trying to curb the spread of the coronavirus, saying they are doing a "fantastic job".
Victorian Premier Daniel Andrews defended Saturday's decision to lock down nine housing towers as another 74 cases were reported in the state on Sunday, following on from the 108 infections recorded the day before - the second highest on record.
NSW reported 14 on Sunday, and all were returned overseas travellers in hotel quarantine, as were the six reported in Western Australia. No other state or territory reported any cases.
Acting Chief Medical Officer Paul Kelly said medical officers from across the country held a teleconference on Saturday night, reiterating their support for their Victorian colleagues.
"They are doing a fantastic job but this is a huge effort," Professor Kelly told reporters in Canberra.
"Right around the country we are offering and providing substantial support to our Victorian colleagues."
Mr Andrews warned the outbreak was unlikely to be contained soon, making it necessary to introduce strenuous measures.
"We are going to see some big days, big numbers in the days ahead," he told reporters on Sunday.
The premier said the controversial hard lockdown was about safety for the residents of the towers - where there have been at least 30 cases - as well as the wider state.
"This is about protection for you and your loved ones and then, by extension, it's about protecting the entire state and we don't make those decisions lightly."
Federal Opposition Leader Anthony Albanese said his heart went out to those people in the public housing lockdown.
"They would be felling scared," he told reporters in Canberra.
"I feel sorry they've been put in this position but Daniel Andrews, I believe, is doing everything that he can to keep them safe."
The resurgence in Victoria has worried other states, leading to bans on Victorians from hotspots entering some states, with the Northern Territory planning to do the same from July 17.
The Australian Medical Association has called for a temporary halt to the easing of COVID-19 restrictions across the country.
"These new outbreaks send a strong signal that the other states should rethink the pace of easing of their COVID-19 restrictions until community transmission in Melbourne is under control to avoid the risk of a similar situation playing out in their own communities," AMA president Tony Bartone said in a statement on Sunday.
"Before rushing back to the pub, the footy crowds, or the big weddings and parties, Australia should pause and play it safe."
Queensland is the latest state to send health workers to Victoria to help.
The inner-Melbourne public housing blocks are being locked down for at least five days for testing of the 3000 residents who will be monitored by 500 police, while stay-at-home orders now cover 12 postcodes.
Victorian deputy chief medical officer Annaliese van Diemen said there was an outbreak of up to 30 cases across the towers, blaming it on close-quarters living and many shared spaces.
Health workers are conducting door-to-door tests.
All international flights are being diverted from Victoria while the troubled hotel quarantine program is put on hold for a fortnight.
At midnight, international arrivals in Sydney were capped at 450 a day in a bid to ensure the hotel quarantining system was not stretched to breaking point.
Returning travellers are likely to avoid Queensland, where the state government is now charging for accommodation.
Prof Kelly said the number of cases across Australia stands at 8449, while associated deaths remain at 104 people, significantly lower than most other countries.
Authorities are urging people to remain vigilant and practise social distancing and increased hygiene measures and to download the COVIDSafe app.
Australian Associated Press