Six new cases are returning travellers in hotel quarantine. Of the remaining cases, one is linked to a known outbreak, eight to community testing and three are under investigation.

There are now 81 active cases in the state.

"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 said 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 centres.

A worker from Learning Centre Pakenham attended the centre for one day while infectious 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 cleaning, contact tracing and risk assessment.

A third Black Lives Matter protester has also tested positive but it is understood they were not infectious during the rally earlier this month.

Friends of the protester will be tested though and retailer H&M at Northland where the protester works will also be closed today.

One of the new cases is linked to the Croydon Family Practice outbreak, taking that total to five.

The figures come a day after Victoria recorded 21 new cases, including 16 overseas travellers in quarantine.

IN OTHER NEWS

Ms Mikakos said while Victoria was recording substantial numbers, she did not think the virus was getting out of control.

"Obviously, I worry about any new cases, whether it's one or whether it's 10, but we have been tracking quite well in Victoria in recent weeks," she said.

"We look for the trends rather than just looking at the numbers on any particular day."

Victoria has been getting large numbers of returned travellers, particularly from Bangladesh, India and Pakistan where COVID-19 cases have recently soared.

NSW has also been getting large numbers of travellers, but has not been recording the same number of cases.

"We test people in mandatory hotel quarantine twice, both near the start of the quarantine and at the end," Ms Mikakos said.

"My advice is that NSW is only testing people at the end, just before they exit the hotel quarantine.

"So that means that it is potentially likely that we will detect more people because obviously, if you've been in hotel quarantine for 14 days and you're only tested at the end, you might have recovered by that point and come up and show a negative result."

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