Two workers at an aged care centre in Melbourne's inner east have tested positive for coronavirus, as thousands of Victorian students returned to school.
The pair, staff members at Lynden Aged Care in Camberwell, were confirmed as having COVID-19 on Tuesday, the health department has revealed.
The cases bring the number of coronavirus infections linked to the facility to three, with a resident diagnosed with the condition on May 19 while being treated at a metropolitan hospital.
The centre has been in lockdown since the first case was confirmed, with extensive testing carried out.
The department says the diagnosed staff members were not identified as close contacts of the original case.
"The source of acquisition for these new cases remains under investigation and all potential sources of transmission will be explored," a spokeswoman said in a statement.
A further round of testing will commence on Tuesday, with close contacts of the workers also asked to enter a fortnight of quarantine.
The development comes as 400,000 Victorian students in prep to year 2 and years 11 and 12 returned to schools on Tuesday after a seven-week hiatus that could change the future of education.
The government says it will examine lessons from the experiment in statewide home schooling.
"Every principal I have spoken to, every teacher, talks about students who have re-engaged; students who disengaged at school seven weeks ago are suddenly embracing their learning," Education Minister James Merlino said.
Mr Merlino has announced an independent analysis to understand what can be learned from flexible and remote schooling, along with a summit of education leaders in June.
Up to 17,500 education staff were tested before the return of students to school, with a teacher at Keilor Downs Secondary College found to have COVID-19.
The teacher tested positive on Friday, but Mr Merlino said they had not been at the school and close contacts weren't identified on site, so no further action was needed.
He also assured parents that the risk of coronavirus at schools was low, stressing the advice of the chief health officer that all students should return for face-to-face teaching.
Opposition Leader Michael O'Brien criticised the return to school under an easing of coronavirus restrictions while Premier Daniel Andrews tells Victorians to continue working from home during June.
"The premier is giving mixed messages," he said.
Years three to 10 go back on June 9, but students of any age with compromised immunity don't have to return.
Victoria recorded five new coronavirus cases on Tuesday before the Lynden Aged Care cases were confirmed.
Three of them were returned travellers in hotel quarantine, one case was found in routine testing and another was attributed to a resident at HammondCare's Caulfield aged care centre.
But that resident and another at the centre who earlier tested positive to COVID-19 have since returned negative tests, HammondCare said.
Victoria has officially recorded 1610 cases, with 56 active cases, while the death toll remains at 19.
More than 437,000 tests have been completed in the state.
Eight people are in hospital, including three in intensive care.
Australian Associated Press
