There are 18 new cases of Covid-19 in the community, the Ministry of Health says.
All of the new cases are in Auckland. Two of them are yet to be linked.
Officials say 16 of today's 18 cases have been epidemiologically linked, and all 16 are in isolation at home or in MIQ.
The 18 cases today follows the announcement of 16 cases on Saturday. Of those 16 cases, half were in isolation and half were in the community while infectious.
Meanwhile, 12 people with Covid-19 are in hospital - four in ICU or a high dependency unit.
There were 13,442 tests in the last 24 hours. The vaccination campaign has reached a new milestone with 5 million doses administered.
Of those, 51,472 doses were given yesterday.
First doses made up 19,350 of yesterday's jabs, and second doses made up 32,122. And 82 per cent of Aucklanders have now had their first dose.
Three new border cases were also picked up. One of them was a new arrival from Russia via UAE on September 21.
The other two are historical cases. One person arrived from Sri Lanka on September 11, with their infection picked up through a day 12 test. The second had arrived from the UK via Singapore on September 22 and tested positive on day 0.
Testing in six Auckland suburbs of interest is continuing. There were 980 tests processed yesterday from Clover Park, Māngere, Favona, Ōtara, Manurewa, and Mount Wellington/Sylvia Park.
Everyone in Clover Park and nearby areas is encouraged to get a test even if they have no symptoms. More than 2140 tests from the suburb have been processed since last Sunday.
In three days more than 1300 tests from Mt Wellington residents have also been processed.
Their closest testing stations include the Auckland Netball Centre in St Johns and a testing station at Mt Smart Stadium in Penrose.
A new pop-up testing centre opens today at the Tuakau Rugby League Club.
The Pukekohe pop-up community testing centre is now at the Pukekohe Netball Centre.
In the last 24 hours there have been 13,442 tests, of which 4,498 were in Auckland.
The Ministry of Health is set to release a statement at 1pm detailing the latest cases of Covid-19.
There was a "glimmer of hope" on Friday when case numbers dropped to nine, but Saturday saw 16 new cases, three of them yet to be linked.
All those infections are thought to have happened when Auckland was in alert level 4 - it's not yet known what the impact of level 3 will be on case numbers. Auckland has been in alert level 3 since Wednesday.
It comes as a Covid-19 modelling expert has warned we're on a "knife edge" as the city continues its drawn-out battle against the Delta outbreak.
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Te Pūnaha Matatini Professor Michael Plank said the number of cases was rumbling along and stubbornly refusing to go away despite Friday's "glimmer of hope".
"It's really on a knife edge and it could go either way depending on how things pan out at level 3."
Plank has urged Aucklanders to take alert level 3 settings seriously, and not to start visiting family and friends, after some residents were seen taking a lax approach to restrictions.
More than 30 people were spotted playing touch rugby in a Mt Roskill park yesterday, and Ponsonby Rd was reportedly "heaving with people".
Cabinet will decide tomorrow whether to change travel restrictions at the city's borders. A decision on alert level settings will be made the following Monday, October 4 - by which time Tāmaki Makaurau will have been in lockdown for 48 days, including two weeks in level 3.
Plank said two weeks was a reasonable timeframe to get a picture on whether the virus was under control.
Epidemiologist Professor Michael Baker agreed, saying it was still too soon to know if level 3 was working due to the time lag between exposure and testing. Yesterday's cases showed what had happened a week ago, in alert level 4.
He said the pattern of cases in the past week or so suggested some ongoing transmission in the community but it was not widespread.
Moving to alert level 3 the numbers were expected to rise "maybe quite markedly" in about two weeks. Reducing the pressure on the virus would see it transmitting widely.
He called for one last big push to stamp out Delta, otherwise New Zealand would need to move to a different strategy - one of managing the virus.
Even with a high vaccination rate, there would still be hundreds of thousands of unvaccinated people in Auckland, enough to sustain very vigorous transmission of the virus. It will put people in hospital and kill people, he said.
"It will also mean trying to keep a lid on it so we don't overwhelm health services in Auckland, Auckland could be at alert level 3 till the end of the year potentially," Baker said.
As of Saturday morning, there were 225 active cases of Covid-19 in the community, and 25 at the border. The most recent case of community transmission was on Saturday.
Locations of interestot released today include visits to Chemist Warehouse in Manukau and Unichem Pharmacy Otara, and a visit to Farro Fresh in Epsom, all since Wednesday when alert level restrictions were loosened.