A dozen Victorian schools have closed due to coronavirus outbreaks, as masks are to become mandatory for students to help stem community transmission.
Victoria recorded 275 new COVID-19 cases on Monday, while an aged care resident in her 80s died from the virus, bringing the number of deaths in the state to 39 and the national toll to 123.
Almost 3000 cases remain active, with 147 people in hospital, including 31 in intensive care.
Sixteen of those in intensive care are on ventilators, a state government spokeswoman told AAP.
After more than a fortnight of triple-digit case number increases every day, including a record 428 on Friday, Premier Daniel Andrews said it was too soon to know if the curve was flattening.
"We had a very big day Friday and then we had a substantial drop-off, even though we had done more tests," he told reporters on Monday.
Mr Andrews said it could take up to two weeks for the effects of the stage three lockdown in Melbourne and Mitchell Shire to be reflected in the figures.
"Let's wait to see how the week unfolds, certainly, we're always happier to report lower numbers than higher ones, particularly when you see testing continue at such a high rate," he said, noting about 26,000 tests were conducted on Sunday.
Most prep to year 10 students resumed remote learning on Monday, while senior secondary students and those with special needs returned last week.
The health department confirmed 12 schools across the state have closed for cleaning and contract tracing due to coronavirus outbreaks, including Trinity College in Colac.
A student at the high school is believed to be a close contact of a worker at Australian Lamb Company abattoir in Colac, where an outbreak has doubled from six to 12 cases overnight.
It comes as students aged 12 or older attending school will be required to wear a mask from Thursday.
Education Minister James Merlino said 1.2 million single-use masks would be distributed to state, Catholic and independent schools.
An order of 1.37 million reusable fabric masks also has been made, with the Department of Education to be among the first to receive a batch.
"Any student who needs a mask will be provided with one," Mr Merlino said.
Teachers will not be required to wear a mask during lessons.
On Sunday, the state government announced face coverings would be mandatory in Melbourne and Mitchell Shire from 11.59pm on Wednesday. People caught without them face a $200 fine.
The premier said wearing a mask was a small price to pay to keep safe.
"Nurses and doctors wear masks when they're treating you. I don't think it's too much to ask Victorians to wear a mask so they don't end up in hospital or contribute to someone else ending up in hospital," Mr Andrews said on Monday.
Meanwhile, a worker at Melbourne Magistrates Court and a worker at Heidelberg Magistrates Court have tested positive to the virus.
"Appropriate cleaning has been undertaken at both sites and support is being provided to all staff," the court said in a statement.
"Court staff have been working in teams so the diagnoses have not impacted court operations."
Contact tracing identified 10 colleagues in total for isolating and testing, but all tests returned so far have been negative.
SCHOOLS CLOSED DUE TO COVID-19 OUTBREAKS:
* Charles La Trobe College
* Drysdale Primary School
* Grovedale West Primary School
* Leibler Yavneh College
* Overport Primary School
* Parkville College - Malmsbury Campus
* Pascoe Vale Girls Secondary College
* Princes Hill Secondary College
* Roxburgh College
* Toorak Primary School
* Trinity College Colac
* Victorian College of the Arts Secondary School
Australian Associated Press