Victoria has ramped up its border restrictions on the opening day of the school holidays.
As Sydney and Darwin experience coronavirus outbreaks, the Victorian government has labelled these cities as 'red zones'.
The majority of NSW, Perth and Brisbane have been labelled as 'orange zones'.
Local government areas along the Victorian and NSW border have been excluded from the new restrictions and remain in the 'green zone'.
Victorian residents coming back to the state from red zones will need to quarantine for 14 days and get tested.
Health minister Martin Foley urged Victorians to remain vigilant despite no local cases have been detected in the state since Friday.
"This is the first time Victoria has had orange and red zones in most Australian states," Mr Foley said.
Those living in Victoria and NSW border communities will continue to be able to access the 'border bubble' by using their driver licence to prove their residential address.
Border residents do not need to apply for a travel permit.
Mr Foley said Victoria Police are front and centre in enforcing the public health response to the coronavirus outbreaks and a request has been put forward to the Australian Defence Force to work alongside police and authorised workers at the borders and in the quarantine household verification.
Victoria Police chief commissioner Shane Patton said police were doing everything they can to ensure there was no unauthorised access from NSW
"We activated Sentinel 8 - that's the standing border security operation that we've had since Saturday," chief commissioner Patton said.
"We deployed staff up there on Friday up around the border area, and it was activated on the Saturday. What that means is we have 260 police deployed in 75 police vehicles - that's normal patrol cars but also highway patrol cars.
"We have a number of automatic numberplate recognition vehicles that have been deployed up there as well. As well as booze buses. So, all of those are working together.
"They're in six zones, spanning from the east to the west of the state, and they're being controlled by local police commanders."
In addition, Victoria Police will also deploy helicopter support for those on the ground in its highly visible and multifaceted operation.
"It's a prevention, detection and enforcement model," chief commissioner Patton said.
"In the past, when we've had lockdowns between regional Victoria and metropolitan Melbourne, we've had two different models; a fixed model otherwise referred to as a "ring of steel", and the highly visible, mobile, prevention, detection and enforcement model.
"That mobile enforcement model gave us greater coverage, it gave us agility, it gave us flexibility. But most importantly it gave us unpredictability.
"When we had that mobile model, and the analysis we did on that, for every thousand vehicles checked, we detected 48 offences against the chief health officer's directions."
Chief commissioner Patton said Sentinel 8 was the most effective model to implement at this time.
"We'll have those 260-odd police officers up there, moving around, as well as all the local police, of course," he said. "And if there's a need to escalate, we will escalate.
Our message is very clear, over the last few days, we've seen a degree of discretion provided in terms of warning, turning people around. That discretion, that window period, is very rapidly closing.Shane Patton
"From here on in, you're going to see a much stricter enforcement."
Victoria Police's coronavirus infringement notices remain at $4,957.
11am: Daniel Andrews back to work with morning press conference
Premier Daniel Andrews has addressed a number of issues at his first press conference since returning to work.
Mr Andrews returned to work this morning after more than three months medical leave following a fall down stairs at a holiday house in the Mornington Peninsula.
He thanked his family as well as the emergency services and medical teams that had helped with his rehabilitation from a fractures spine and broken ribs.
"I have spent four months doing rehab, getting fit and healthy to get back to work for the people of Victoria," he said. "My spine is basically healed. As far as my ribs go, they will take another three months or so. I was keen to be off all significant medications as quickly as possible.
"It's only human that when you have a big and traumatic event, you look at what you're doing and assess what's important and are reminded what's important.
"I've said a few times, my family everything to me but every Victorian family means a lot as well. I've made it clear to Victoria that I'm not the sort of person who quits or cuts and runs. I'm up for it as long as Victorians want me to do that important work."
Mr Andrews slammed people, including members of the opposition, who had spread stories about a cover-up being part of his absence.
"We've been up front and clear," he said.
This stuff is vile, for those who tried to politically weaponise this, they're irrelevant to what I do, I won't waste my breath on them.Daniel Andrews
Mr Andrews praised the work done during his absence by acting premier James Merlino and other government workers. He said he was very supportive of how Mr Merlino had handled pandemic-related questions.
"I have been in regular contact with the acting premier, senior staff and colleagues but you can't back seat drive," Mr Andrews said. "If I am on leave and getting well, then I am on leave and getting well.
"We did speak multiple times a week but it wasn't daily and in early stage would have been less than that (multiple times a week).
"It's not appropriate to be having bureaucratic workers and teams working for two bosses. (Taking leave) is not an easy thing to do but when doctors tell to submit to advice, you do as you're told."
Turning his attention to the COVID-19 Delta variant and vaccinations, Mr Andrews encouraged people to get vaccinated and said he was address the supply of vaccinations in this evening's national cabinet meeting.
"This Delta variant is twice as infectious moves rapidly," he said. "By the time you get to someone who has a case, they have infected their family and other people, some who they don't know.
"Our way out of this and back to something approaching normal is to have a significant percentage... of people vaccinated.
"We have got a supply problem and have done more than any other state but no one can be happy so few are vaccinated. I intend to raise the issue of vaccine supply (at the national cabinet meeting) as I hope will every other first minister."
Victoria has seen two new coronavirus cases in the past 24 hours.
Both of the cases were recorded in hotel quarantine. The last coronavirus cases locally transmitted in Victoria was recorded on Friday.
The new cases leave Victoria's active COVID-19 case tally at 45.
Over the weekend, Victoria also pushed past one million COVID-19 vaccinations delivered with 14,294 administered in the past 24 hours.
Victorians also received 17,617 test results in the past 24 hours.
The latest Department of Health data comes as premier Daniel Andrews prepares to return to work.
Mr Andrews has been on medical leave for more than three months after slipping on stairs at a Mornington Peninsula holiday rental in March.
He suffered broken ribs and a fractured spine in the fall.
On Sunday, Mr Andrews shared his his story in a video published to his social media pages.
"I'm coming back this week. I'm fit, I'm strong and I'm healthy," he said.
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