A leading epidemiologist says news of three new community cases are concerning and the next few days will be critical for guiding the Government's response.
The three new community cases announced Tuesday are all household contacts.
One of the cases is a Papatoetoe High School student deemed a "casual plus" contact of the initial high school case. She hasn't been at school.
The other two cases are siblings, an infant and a teenager who recently finished school and has been working at Kmart Botany.
The Ministry of Health said 31 staff at the Kmart store had been identified as close contacts and were isolating.
University of Otago epidemiologist professor Michael Baker said it was always worrying when there were cases in the community - and the next few days were critical in deciding what to do next.
"The information you really want to know is amongst those contacts whether any of them test positive. If those in their immediate work environment don't test positive that's generally quite good news. It doesn't mean you're in the clear but that would be a good sign," he said.
University of Canterbury professor Michael Plank said it was not surprising to see other cases emerge from an already infected household.
"The good news is that these students haven't been back to school since the start of the outbreak so if you've got kids at Papatoetoe High School you don't need to worry."
The situation shows why the contract tracing system and Covid Tracer app are so important.
"If you've scanned into Kmart [Botany] you've got that reassurance that you'll get the message [notifcation] if you were there at a time when this case was also in the store."
He said it would be useful to confirm the epidemiological link between the case that was identified earlier on Tuesday and the ones that were identified previously.
"We know they go to the same school but they weren't close contacts, they're not in the same classroom. It would be useful if we could try and identify exactly when that contact occurred that the infection was passed on"
Infectious disease physician at Auckland Hospital Mark Thomas said the chance of other contacts at the store testing positive was "relatively small".
"It has to be followed up so if there has been any unlikely transmission to other casual plus contacts they get identified and managed."
Meanwhile, Auckland University associate professor Dr Siouxsie Wiles is calling for Auckland to be moved to alert level 2 following the latest cases.
She told Stuff this would place limits on gatherings, to "stop super-spreaders" from infecting others.
"The question will be whether they can contain the cases through track and tracing," she said.
"The best move is to go to level 2 to stop super spreaders."