Victoria has recorded 24 new locally acquired coronavirus cases on the first day of stricter lockdown measures in Melbourne. 

Overnight, the ACT was declared an extreme risk zone under Victoria’s travel permit system, after its COVID-19 outbreak grew to 28 cases. 

Anyone who has been in the ACT in the past 14 days cannot enter Victoria without an exemption or valid permit.

The health department on Tuesday confirmed 21 of the new Victorian cases are linked to known outbreaks, while the remaining three are mystery infections.

Fourteen were in quarantine during their infectious period.

A case was also recorded in hotel quarantine, bringing the total number of active infections in the case to 227.

Some 31,519 tests were processed in the 24 hours to Tuesday morning, while 25,742 Victorians received a vaccine dose at a state-run hub.

It comes as the state government extended Melbourne’s lockdown by two weeks, reintroduced a curfew between 9pm and 5am and closed playgrounds in an effort to contain the city’s latest outbreak of the Delta coronavirus variant. 

Exercise has also been limited to two people, large-scale construction restricted to 25 per cent of staff and people will not be allowed to remove their masks to drink alcohol in public.

From 11:59pm on Tuesday, authorised workers will be required to carry permits. 

Premier Daniel Andrews on Monday 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 Melbourne was “right on the cliff edge” of the outbreak getting out of control.

He said a “grumbling” number of daily cases could end up being 100 in a fortnight, or thousands in a month.

Greater Darwin and Katherine, which entered a 72-hour lockdown on Monday, were also reclassified as red zones, meaning anyone arriving in Victoria from the local government areas will need a permit and must quarantine for 14 days. 

Meanwhile, Victorian parliament’s lower house has deferred sitting after advice from Professor Sutton. 

The upper house, however, will gather on Tuesday to debate and vote on whether it should continue to sit.

There are currently more than 14,200 close contacts self-isolating across Victoria and more than 540 exposure sites.

AAP