Coronavirus hotspots in Melbourne will be put into lockdown from Wednesday night in a desperate effort to contain an outbreak of the deadly disease in the state.
There will also be no international flights into Melbourne for the next fortnight to help curb the state's high infection rate.
It comes as Premier Daniel Andrews announced a judicial inquiry into the state's management of hotel quarantine after an "unacceptable number of cases" through late May and early June were directly linked to infection control breaches.
Victoria recorded 64 new cases of COVID-19 on Tuesday, down from 75 on Monday, capping a fortnight of consecutive double-digit daily increases.
The majority of new cases have been due to community transmission, prompting the Premier to reintroduce stay-at-home orders across 10 postcodes from 11.59pm on Wednesday until at least July 29 in a bid to contain an "unacceptably high" number of infections detected in the past few days.
The postcodes that will be under stage three restrictions are: 3038, 3064, 3047, 3060, 3012, 3032, 3055, 3042, 3021, 3046.
Residents in these postcodes will be able to leave their homes for only four reasons: to purchase food and other essential items; for exercise; for medical care or care-giving; or to go to work or school.
People who must attend work in those postcodes or provide care to someone there are allowed to enter.
"We need every Victorian family, particularly those in these lockdown postcodes, to know and understand that while this is deeply inconvenient for you, you are making a massive contribution for the whole state and indeed the whole nation," Mr Andrews said.
"If you are sick, you cannot go out. The only thing you should be doing if you are sick is getting tested."
Following a series of crisis meetings on Tuesday, the Premier requested that all international flights be diverted from Melbourne for the next fortnight, to reduce the number of arrived travellers who need to be placed in hotel quarantine.
"I haven't got the answer from the Commonwealth yet, but I'm pretty sure the answer will be yes, there will be no further flights arriving," he said. "Today's flights will be the last ones for a period of two weeks."
Face-to-face learning will continue in schools within the 10 lockdown postcodes for now, Mr Andrews said.
"On the advice of the Chief Health Officer we are seeing no real evidence of transmission between kids and adults," he said. "We are seeing no real evidence that school attendance is a big driver of the spike in cases."
The Melbourne suburbs in lockdown from midnight July 1
3012: Brooklyn, Kingsville, Maidstone, Tottenham, West Footscray
3021: Albanvale, Kealba, Kings Park, St Albans
3032: Ascot Vale, Highpoint City, Maribyrnong, Travancore
3038: Keilor Downs, Keilor Lodge, Taylors Lakes, Watergardens
3042: Airport West, Keilor Park, Niddrie
3046: Glenroy, Hadfield, Oak Park
3047: Broadmeadows, Dallas, Jacana
3055: Brunswick South, Brunswick West, Moonee Vale, Moreland West
3064: Craigieburn, Donnybrook, Mickleham, Roxburgh Park, Kalkallo
Mr Andrews said police would enforce the lockdowns and on-the-spot fines would be issued for those outside their homes without a permitted reason.
"This is the public health advice. This is what we must do now. If we do not do this now then I won't be locking down 10 postcodes, I will be locking down all postcodes," he said.
Victorian Chief Health Officer Brett Sutton described Victoria's alarming surge in cases as a "heartbreaking turn in the epidemic".
"That is a significant doubling rate and it was that trend and the fact that we had to turn it around that prompted me to take these actions," he said. "These are the right public health actions and we know that they can work."
Of the new cases on Tuesday, 13 are linked to known outbreaks. Twenty new cases have been identified through routine testing and another 31 remain under investigation.
Mr Andrews said more than 93,000 tests have been conducted since the testing blitz was undertaken in hotspots last week, and about 37,000 doors have been knocked on.
More than 230 new cases of coronavirus have been recorded since last Thursday, with the majority among residents in Broadmeadows, Fawkner and Albanvale.
But the Premier said almost 1000 residents in suburbs deemed danger zones had refused to get tested.
"I do feel obliged to inform you that in Broadmeadows and Keilor Downs alone, some 928 people refused to be tested," Mr Andrew said.
"Now, I can't change that. That's happened. All I can do is encourage those people come forward and get tested today."
On Monday Professor Sutton warned the coronavirus outbreak "will get worse before it gets better" after 75 new cases were revealed – the fourth-highest number since the pandemic began and the highest since March.
Mr Andrews and Prime Minister Scott Morrison spoke at length on Monday about the Victorian outbreak as the pair agreed on the deployment of 800 federal workers to help under-siege state authorities bring the situation under control.
The federal government believes, on the advice of the Australian Health Protection Principal Committee, that suburb-by-suburb action is needed.
The Morrison government agreed to provide 100 managers to support community engagement, 500 staff to form public engagement and door-knocking teams, and 200 clinical staff to undertake testing at fixed sites, to release clinical staff to participate in mobile testing in hotspots.
Mr Morrison on Monday pledged to give Mr Andrews anything he needs to combat the outbreak.
Professor Hamish McCallum from Griffith University said the state was experiencing a second wave of the virus.
"The question is whether it is a ripple, or the start of a tsunami," he said.