Victoria has recorded a massive spike in Covid -19 cases, with 288 new infections recorded overnight.
The state's total number of cases now sits at 3397, overtaking NSW as the state with the highest total of cases.
Of the new cases, 26 are connected to known outbreaks and 262 are still under investigation.
There are 47 Victorians in hospital, with 12 of those in intensive care.
"I know there will be great concern about these numbers. People will feel deeply concerned to see that number as high as it is," Premier Daniel Andrews said.
"We didn't take this step to return to staying at home, except for the four reasons for metropolitan Melbourne, because the numbers were stable, we didn't take that step because we didn't have a problem, we took that step because we knew it would need to get worse before it got better and that unless we took those steps we simply wouldn't be able to bring a sense of control to this.
"We would not be able to see a stabilisation and then a driving down of those case numbers stop at the same time, no-one should underestimate how significant, how big a challenge we all face."
Andrews also noted that the state conducted 37,588 Covid-19 tests yesterday.
"The sheer volume of testing we are doing, I am confident by that. That is a massive number of tests," he said.
"To get those taken and get them processed, that means you will find more virus because we know the virus is out there across metropolitan Melbourne.
"The key point here is to acknowledge that these numbers will need to increase, they will need to get to a peak before it is we can stabilise them and drive them down."
Victoria's chief health officer Brett Sutton has labelled today's virus spike an "ugly number".
"We have talked about the fact that we would expect an increase in numbers over time and there was no room for complacency at any point in time," he said.
"That's as true today as it has been right up until now. We may well get worse numbers to follow."
Sutton praised the state's high rate of testing and the contact tracing that is being undertaken.
"It is an indication of the transmission that was occurring a week ago that showing up in the numbers today and we may well see it worsen before it gets better," he said.
"We know that there are continuing hot spots in the north-west corridor in particular, of recent days there has been an uptick, especially in Roxburgh Park and Craigieburn and Truganina.
"There are some postcodes that are really significant and showing up in terms of transmission.
"People in those areas in particular should bear in mind that any symptoms, really, should prompt you to be testing stop at that is true across Victoria."