A third Black Lives Matter protester has tested positive to coronavirus in Victoria, though it's understood they were not infectious when they were demonstrating.
Community transmission of coronavirus in Victoria remains, with 18 new cases recorded taking the state's total to 1780.
Of the 18 new cases, six are return travellers are in hotel quarantine.
Of the remaining cases, one is linked to a known outbreak, eight to community testing and three under investigation.
A third Black Lives Matter protester has also tested positive, but it is understood they were not infectious during the protest.
Friends of the protester who all attended the rally earlier this month will be tested.
There are now 81 active cases in Victoria.
"Clearly, we do have community transmission in Victoria and I want to reiterate the message to Victorians to take this issue seriously," Health Minister Jenny Mikakos told reporters on Thursday.
"Many of these cases are people with very, very mild symptoms, but they've done the right thing and gone and been tested and that is how we will manage the spread of the virus."
Of the routine testing cases, one is a childcare worker and another is a child, forcing the shutdown of two childcare centres.
A worker from Learning Centre Pakenham attended the centre for one day during infectious period and it will now be closed for the rest of the week.
The other is Guardian Childcare and Education in Prahran, where an infected child attended for one day.
That centre will be closed today for deep clean, contact tracing and risk assessment.
Retailer H and M at Northland where the protester works also will be closed today.
One of the new cases is linked to the Croydon Family Practice outbreak, taking that total to five.