Victoria has experienced its worst day yet since the coronavirus outbreak, recording 532 cases overnight.
Premier Daniel Andrews said there had been a further six deaths.
He urged anyone with symptoms to get tested, saying it was the right thing to do.
"If you have symptoms get tested," Mr Andrews said.
He said the virus did not discriminate and everyone had a part to play in curbing the spread.
Mr Andrews urged people to say home from work while awaiting test results.
If they test positive he asked for people to talk to people they had been in contact with.
Prime Minister Scott Morrison said he supported Mr Andrews' lockdown.
"If you're sick, you simply can't go to work," he said.
Member for South West Coast Roma Britnell has called for greater detail about cases assigned to local government areas.
She said a positive case was added to the Warrnambool City Council area, but local police said they have no information about a positive case.
"Police have said in the media this morning that they have no instructions to check on a person in the Warrnambool area to ensure they are complying with isolation rules, indicating this person isn't actually in the Warrnambool area," Ms Britnell said.
"But then we have a school confirming they are linked to the case - there is mass confusion, there seems to be a breakdown in communications from the department.
"It's creating unnecessary angst in the community."
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