Of the 24 new cases, 14 were in isolation throughout their infectious period and 10 were infectious in the community.

In total, 21 of the 24 new cases have been linked to the current outbreak, with three under investigation.

There were 31,519 tests returned and 25,742 vaccinations administered, but Premier Daniel Andrews said this was not enough.

"That is not high enough and I would ask every single Victorian, regardless of where you live, your circumstances, if you register any symptoms at all, please come forward and get tested," he said.

There are currently 227 active COVID-19 cases in the state.

50 current active cases in Victoria are under the age of 10.

Of the new cases:

There are currently more than 14,200 close contacts across Victoria and more than 520 exposure sites.

700 of those were cleared yesterday and 8000 are expected to be cleared over the next few days.

Kate Matson from the health department says there's been five mystery cases recently in the St Kilda area.

"These cases aren't linked by age, they're not grouped by faith. They aren't all in the same book club," she said.

"There is nothing linking these cases other than geography.

"We're not seeing testing rates high enough and are concerned there are cases here that we do not know about."

There remains just two exposure sites in regional Victoria, both of which are in Bacchus Marsh.

There were a number of coronavirus wastewater detections in areas without known cases: the Sunshine West industrial area, Boroondara, Truganina/Williams Landing and Shepparton.

Meanwhile, Melburnians are now under stricter lockdown measures including a reimposed curfew and the closure of playgrounds, as health authorities fight to control the city's worsening coronavirus outbreak.

WARRNAMBOOL COVID NEWS

People living in Melbourne are required to stay at home between 9pm and 5am after Premier Daniel Andrews announced a night curfew which came into effect at 11.59pm on Monday.

The city's lockdown has been extended for another two weeks until September 2, with playgrounds and skate parks closed, exercise limited to two people and authorised workers required to carry permits.

Police busted two private gatherings in Melbourne overnight in what was otherwise a "relatively quiet night" said Victoria Police Chief Commissioner Shane Patton.

Additionally, large-scale construction will be restricted to 25 per cent of staff and people will not be allowed to remove their masks to drink alcohol in public.

Mr Andrews said there was "no choice" but to toughen restrictions given increasing mystery infections, the number of children infected and several illegal gatherings at the weekend.

Chief Health Officer Brett Sutton said "we are right on the cliff edge here" as he warned a "grumbling" number of daily cases could end up being 100 in a fortnight, or thousands in a month.

Meanwhile, Victorian Parliament's lower house has deferred sitting until next week after advice from the Chief Health Officer, however the upper house will sit on Tuesday.

See all the exposure sites here.

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