Melburnians will soon be subject to even stricter virus rules, as the state’s sixth lockdown is extended for a further two weeks.

A curfew will be imposed across greater Melbourne and work permits will be re-introduced, with Victoria Police cracking down hard on rule breakers.

The lockdown, which has already been extended, is now set to end on September 2.

It comes as Victoria confirmed 22 local virus cases on Monday, with the source of five remaining a mystery.

Only 14 cases were in quarantine throughout their infectious periods – with Melbourne 10 days into a lockdown.

Some 29,986 tests were processed in the 24 hours to Monday morning, while 19,880 Victorian received a vaccine dose at a state-run hub.

Premier Daniel Andrews said the virus was spreading undetected in the community, with 12 or 13 different chains of transmission as well as “too many” mystery cases.

“We are at a tipping point. There is simply no option today but to further strengthen this lockdown and to – on the advice of the chief health officer – extend it for a further two weeks,” he said.

“We have greater risk, greater uncertainty, and therefore we have no choice but to follow advice that says we need to go harder, and we need to go longer, in terms of this lockdown.

“I don’t want to have to stand here and report deaths. I don’t want to have to stand here and report hundreds and hundreds and hundreds of cases every day and perhaps an even greater number of people in hospital.”

Tweet from @DanielAndrewsMP

As health authorities race to track down the sources of a growing number of unlinked infections, additional rules will also be imposed.

From Monday night, a curfew will run from 9pm-5am. Essential workers will also need permits, with staffing on big construction sites capped at 25 per cent of their usual numbers.

Playgrounds, skate parks and public exercise equipment will also close.

Chief health officer Brett Sutton said the tighter measures were for several reasons, rather than a single event.

“It is in response to a number of things that are showing that we are at the brink and we need to step back from the brink,” Professor Sutton said.

“We are maybe just keeping up with this outbreak but we aren’t ahead of it in the way we need to be to achieve control.”

‘Selfish, disappointing and outrageous’

Mr Andrews said he was angry about instances where people had breached or bent the rules, particularly an engagement party held in inner-Melbourne at the weekend.

“Because there’s video footage of a particular engagement party, I think it’s only fair that I make a couple of comments and explain to you why I’m angry about that event,” he said.

“It shouldn’t have happened. Some of the commentary in the video is just blatant. What makes me really angry about it is there are 69 people at that event and no matter what you’re told or what you read, the fact is there has been transmission at that event.”

Mr Andrews said the party, which has led to at least two positive cases, was already a transmission site. It might yet become a super-spreader event.

“Our contact tracers, who are working their guts out for all of us, will have to spend literally thousands of hours dealing with hundreds and thousands of people connect to that engagement party,” he said.

“That is the work they must do but it is all entirely preventable. That is what makes me angry and disappointed.”

Victoria Police Commissioner Shane Patton said the “selfish, disappointing and outrageous” breach would likely lead to hundreds of thousands of dollars in fines for those who attended.

Mr Andrews said that while it was unlikely the state will get 100 per cent compliance, harsher enforcement would make people reconsider breaking the rules.

“That engagement, if they had their time again knowing it would cost them $300,000 they might not do it, I think people will make better decisions, that’s what I’m asking for,” he said.

Pop-up beer gardens will also be banned, with Victoria Police to conduct licence reviews after some venues created walk-up bars in the CBD to sell takeaway alcohol from the footpath.

“There will be no more drinking alcohol with your mask off in those circumstances,” Mr Andrews said.

Religious broadcasts will also face stricter limits, permits for authorised work will be re-introduced and outdoor play areas will be closed.

Across Victoria, the number of exposure sites exceeds 530. See all of the latest here.

-with AAP