NSW has recorded 31 new community cases of Covid-19.
Thirteen of those cases were in the community during their infectious period.
"We are anticipating an increase in the numbers over the next few days," NSW Premier Gladys Berejiklian said.
More than 76,000 people were tested in the past 24 hours up to 8pm last night, a record for the state.
NSW recorded 31 new locally acquired cases of COVID-19 in the 24 hours to 8pm last night, of which 27 are linked to previously confirmed cases. pic.twitter.com/Uiwda2a5SQ
Berejiklian has again urged the more than five million people in lockdown in the state to stay home as health authorities grapple with more than 200 coronavirus cases.
"What we look at is how many cases we had that were not in isolation either completely or partially… last night's figure of 13 is concerning, and that is something we are working to address," she said.
"I want to stress to the community, stay at home and do not leave the house unless you absolutely have to.
"Please make sure that if you are a worker, doing an essential job, that you do not turn up if you have the mildest of symptoms."
"The next few days are critical, because we know that what we're doing until this point in time has been mopping up the last few days leading into the lockdown, we anticipated that and I am relieved I have to say that the case numbers were not as bad as what they could have been."
The Premier said she was expecting the "tide to turn" by early next week in terms of the number of positive cases that were in isolation, opposed to those who have been active in the community.
New cases in Queensland
Queensland has recorded three new community cases of Covid-19
One is the partner of a known case and was already in isolation.
The other two are a mother and daughter from Carindale, in Brisbane. Premier Annastacia Palaszczuk said those cases were concerning.
"They have symptoms and were tested yesterday. They have been out quite extensively around Brisbane," Palaszczuk said. "We really need our contact tracers... to really get on top of this issue quickly today."
Chief health officer Dr Jeanette Young said the mother and daughter had been "extremely helpful" in helping health authorities trace their potential place of infection.
Brisbane and the Moreton Bay region will remain locked down for another 24 hours.
Palaszczuk said contact tracers needed the extra time to get a handle on the new cases. A further easing of restrictions would be discussed tomorrow.
"I want to thank everyone for doing the right thing but as you can see, we've just got a situation at the moment that has just come in and we really need to give the people, our contact tracers, the time to do that," she said.
Noosa, Sunshine Coast, Ipswich, Logan, Redlands, Gold Coast, Scenic Rim, Lockyer Valley, Somerset and Townsville will see their lockdown end at 6pm tonight.
However, everyone in those areas will still need to wear masks for at least the next two weeks.
"Everyone will have to carry a mask on them and wear that mask whenever they're outside of their home... that means going to shopping centres, hospitals, aged care facilities, churches, everywhere else," the Premier said, adding that the measure was an "added protection" for the state.
South Australia records one new case of Covid-19
South Australia has recorded one new local case of Covid-19 overnight, as well as a man who is a returned traveller.
Premier Steven Marshall said the new case was another child of the miner who returned to South Australia last Friday.
The Perth and Peel regions in Western Australia will today find out today if they can emerge from their four-day lockdown.
Premier Mark McGowan ordered the regions into lockdown on Monday after a Delta strain case was discovered on Sunday. Two more cases were found on Monday, prompting the lockdown.
A fourth case was discovered on Wednesday but that person had already been in isolation.
The state has now gone 48 hours with no community cases, raising hopes the lockdown will end tomorrow morning.
This week's lockdown is the state's third this year.
In the Northern Territory, Chief Minister Michael Gunner revealed the state's seventh case, a man in his 50s who spent time in the Darwin community over the weekend, including an evening at the Buff Club, had lied about his whereabouts.
The man had been under stay-at-home orders as he waited to go to the state's quarantine facility, but visited a corner store.
"He broke the law before this happened and he lied about it," Gunner said during a late press conference on Thursday evening.
The new exposure site, the Stuart Park corner store on Australia St in Darwin, is now classified as a casual contact exposure site.
The development threatened to affect the state's decision to ease or extend lockdown for some areas, but Gunner confirmed this afternoon that Darwin and Alice Springs would see their lockdown end at 1pm local time today.
New South Wales is halfway through its two-week lockdown, but authorities say the state has a long way to go before restrictions are eased.
Twelve of yesterday's 24 new cases were in the community while symptomatic, NSW Premier Gladys Berejiklian said, warning "that needs to stop".
"The purpose of a lockdown is to stop community transmission, and that won't happen unless people stop interacting with one another, especially if they have symptoms," she said.
"If we want the lockdown to succeed, all of us to have minimise our movements, all of us to have minimise our interaction with others, as difficult as that is, to make sure that the lockdown is successful," she said.
University of NSW epidemiologist Mary-Louise McLaws told the ABC the Delta variant was the "fastest and fittest" mutation that the world had ever dealt with.
Due to this, authorities would need to see at least three to five days of no positive cases in the community to consider easing the lockdown, she added.
More than five millions people across Greater Sydney have been in lockdown since Saturday, with the lockdown due to end next Friday.
Those in lockdown are only permitted to leave their home for a number of key reasons, including for outdoor exercise.