Ballarat will be plunged back into lockdown after less than a week of slight freedom.
Premier Daniel Andrews announced the localised lockdown would be implemented at 11.59pm Wednesday.
It will last for at least seven days and the rules will be the same as we previously saw and the same as metropolitan Melbourne. However, a curfew will not apply.
There have been two additional cases overnight, both household contacts of yesterday's case that was announced.
It is expected more cases will be confirmed over the coming days.
There will once again only be five reasons to leave home.
Making the announcement, Mr Andrews said there had been a number of detections of the virus in Ballarat's wastewater that had not yet been accounted for.
Meanwhile, Greater Shepparton will emerge from its lockdown at midnight tonight.
"It is not the news Ballarat wanted to hear but it's the decision we need to make," Mr Andrews said.
"If we allow it to get away in one part of regional Victoria becomes a threat and a risk to all of regional Victoria. We simply can't have that happen."
Chief Health Officer Brett Sutton said it was likely there would be more cases arise in Ballarat as part of the outbreak.
"There are likely to be more cases," he said.
Meanwhile, the Greater Shepparton area will join the rest of regional Victoria and com out of lockdown from 11.59pm on Wednesday night.
"They've done an amazing job and this decision has come from the great work from the community," Mr Andrews said.
Victoria has recorded 423 more locally acquired COVID-19 cases and two deaths.
Of the local cases, 149 have been linked to known cases and outbreaks.
There were 54,649 test results received on Tuesday, and 41,856 doses of vaccine were administered at state-run sites.
Victoria's active coronavirus case tally now sits at 4,038.
See where all the exposure sites are here
