NSW has recorded its worst day with 466 new local cases of Covid-19 and four new deaths.
More than 12 million Australians are now under lockdown as the Delta strain wreaks havoc across the nation.
AMA NSW President Dr Danielle McMullen has told ABC News "mystery" cases popping up in the ACT and Victoria had experts worried.
"It is really concerning. Obviously, if we look back at NSW nine weeks ago, we remember that time where we had a handful of cases, but a number of them infectious in the community and no clear source of transmission," she said today.
"It is very easy for the Delta strain to get out of control in those sorts of situations and so I do think that other Governments need to learn from us and to and to take quick, decisive action, and so does the community.
"I know Australians are all tired of Covid. We all wish it was over and we are all missing our loved ones, but across these areas that are affected – the ACT, Victoria, here in NSW – we need to be quickly and strongly taking action to lock down and get numbers under control."
New South Wales
NSW Premier Gladys Berejiklian announced today the state recorded 466 new local cases of Covid-19 and that at least 60 were in the community while infectious.
NSW's death toll has risen again with four new deaths recorded overnight.
They include a woman in her 40s at Concord Hospital, a man in his 70s with pre-existing conditions, a man in his 80s and a woman in her 70s.
She said it was a "really, extremely concerning situation".
She added the number of cases in the community while infectious was likely to rise, "given the number of cases under investigation".
In Dubbo and the surrounding areas of NSW, 26 new cases were recorded overnight.
As a result, it is likely the lockdown will be extended in that area, Berejiklian said.
The Hunter/New England region had 16 cases overnight.
Armidale, Tamworth and the Northern Rivers still remain at zero cases, but despite that, the Armidale region's lockdown will likely be extended by at least another week.
Yesterday, NSW recorded 390 new cases and two deaths.
It was the worst day in the outbreak – but Berejiklian warned case numbers would rise in the days ahead.
"I anticipate, given the large number of cases we have had in the last few days, unfortunately, this trend will continue for at least the next few days," Berejiklian said yesterday.
"It means all of us have to work harder to make sure we start and follow the rules."
Greater Sydney and multiple regional Local Government Areas (LGAs) are living under strict lockdown conditions, including Armidale, Dubbo, the Newcastle and Hunter region, the Northern Rivers, Tamworth and parts of western NSW.
Victoria has recorded 21 new Covid cases overnight. Three of those cases are in hospital, with one in ICU.
All are linked to previously reported cases, and 11 were in quarantine during their infectious period.
Yesterday, Victoria recorded 15 new local cases.
The list of exposure sites in the Victorian capital has ballooned to 450 as hopes of the lockdown ending on Thursday fade.
Melbourne's lockdown has been extended until at least next Thursday.
ACT have recorded just one new cases of covid-19 today, bring the total number to eight active cases.
The Australian capital entered a snap seven-day lockdown earlier this week after a confirmed Covid-19 case from an unknown source was detected in the ACT.
Yesterday the capital recorded four new Covid-19 cases.
As Canberra enters the seven-day lockdown, local media reported three close contacts of the original unknown Covid-19 case had tested positive.
Canberrans will only be allowed to leave their homes for essential reasons, including essential employment, healthcare, essential groceries and supplies and up to one hour of outdoor exercise.
There have been six new local cases recorded in Queensland overnight.
In good news for the state, all of those cases are linked to the Indooroopilly cluster and all were detected in home quarantine, meaning none were in the community while infectious.
Of today's six new cases in Queensland, one is a 1-year-old sibling of a child who is already in hospital.
Five adults linked to both Brisbane Boys' Grammar School and Ironside State School are also among today's cases.
On top of today's six local cases, a seventh – a 4-year-old child who has come from Cambodia and has been in hotel quarantine – was also announced.
Queensland's Deputy Chief Health Officer Dr James Smith has confirmed a "significant proportion of children" have been hit by the current Delta outbreak.
He said the 1-year-old among today's cases was in a "stable" condition.
Yesterday, Queensland recorded seven new locally acquired cases of Covid-19, all linked to the existing cluster and detected while in home isolation.
Thousands of Queenslanders are in isolation, but a large number of those will be released as the 14-day period since the beginning of the cluster ticks over.
The state's Delta outbreak - which originated at the Indooroopilly State School and has now reached 137 - has largely been contained, but Premier Annastacia Palaszczuk fears the NSW crisis could breach the border.
On Thursday the Premier told Queenslanders "do not go" to NSW as she again threatened to ramp up border closure restrictions.