Prime Minister Jacinda Ardern said seven people were injured in the terror attack at an Auckland supermarket yesterday and three people are still in a critical condition.

Five people are in hospital - including the three critically hurt. Two people are recovering at home.

Police Commissioner Andrew Coster said there was nothing unusual about the subject's routine - travelling by train from Glen Eden to the New Lynn Countdown.

He arrived at 2:20pm at the supermarket and was shopping normally for about 10 minutes.

A timeline is being established from CCTV footage.

Coster said the man's actions yesterday even suggested he was planning for a future attack.

Long-term surveillance is very difficult, Coster said.

"Surveillance is different from a security detail."

"These are highly-trained specialists ... they are very good at what they do," Coster said of the teams who tracked the terrorist.

Coster said police responded within 60 seconds of people shouting. The attack started 60-90 seconds prior to that.

All of the injuries suffered by the seven victims were due to the offenders' actions, Coster understood.

Terrorist had 'high level of paranoia'

He said the subject displayed a "high level of paranoia".

"We have had no legal grounds to detain this subject," Coster said.

He said police staff acted in the way expected of them.

He acknowledged the first aid given to the victims by professionals and members of the public.

Surveillance staff were not able to move around the supermarket with the man because of the Covid outbreak in Auckland, Coster said. They waited at the entrance.

A trained paramedic played a key role in giving treatment. One member of the public had advanced level of first aid training.

He recognised the staff at the supermarket will be shocked and police will be visible in the coming days.

Asked whether the person knew if they were being tailed, Coster said there were two options, either it was planned or opportunistic. Coster said we may never know however, he said the man was highly conscious of surveillance.

The scene examination was still underway. CCTV footage showed him taking a kitchen knife off the shelf and using it. Coster said nothing suggested to him that any other weapons were used.

Coster said the officers had acted in "exactly the way we would have expected them to".

While there were many people with concerning ideologies, Coster said there were few who reached this level of concern.

The terrorism threat level remains at medium, he said.

"Cases of this type are highly unusual," Coster said.

Police would be conducting more visible patrols around supermarkets

"I have no doubt the first aid rendered has made a very significant difference for the victims in this case."

Coster said a lot of misinformation had spread in the community. This case is an outlier and no one else was being looked for in relation to the event.

Events like this can bring out disturbing attitudes from a few people, Coster said, and police would be visible over coming days.

"This incident should not give rise to undue concern amongst the public."

Ardern said work had been done by Crown law to release more information. However, the court has given the family a 24-hour window before that.

There are details relating to the man's immigration which she cannot share yet, along with his name although she had not intended to publicise their name.

The terrorist's history in NZ

The man arrived in New Zealand in October 2011, when he 22 and travelling on a student visa.

His "extreme" views were not known at the time he arrived.

He was arrested in May 2017 at Auckland Airport where it was believed he was heading to Syria.

He was released on bail after being arrested on multiple charges.

In September 2018, he was sentenced to 12 months' supervision on the initial charges.

That same month, ministers were briefed on work to be done on counter terrorism legislation.

In July 2020, the Crown was unsuccessful in laying another charge on the knife purchase and objectionable material.

He also assaulted Corrections officers and faced charges on this.

Officials met a number of times to address the risk posed by this man, with concern over reducing legal ability to do this.

Work on his immigration status was underway at this point and more details were expected to be released tomorrow.

On July 6, he was sentenced to 12 months' supervision.

He was required to attend rehabilitation. GPS monitoring was sought but not successful.

"Throughout this period officials met a number of times to consider what avenues could be pursued to address the risk posed by this individual and to prepare for the potential that we may run out of legal avenues to detain him," Ardern said of earlier this year.

Ardern says she hopes to share more detail with the public tomorrow. That will be dependent on legal suppressions currently in place being lifted.

Police worked alongside NZ SIS, Ardern said. Police identified that he could be arrested without a warrant.

In July, he was released into community and surveillance started. Ardern was given an update in late July.

"I was briefed on this particular work in May 2021. I sought further advice on whether provincial orders could be used," she said, but was later told that they couldn't be used, nor had the man had a psychological assessment.

In late August, Coster and others raised the issue of holes in the counter-terrorism legislation.

The IPCA and Coroner will be an important part of this work going forward with this case, she said.

As soon as Parliament resumes, Ardern said no later by the end of this month, holes in the counter-terrorism legislation would be addressed.

We owe it to everyone to have other people look at this case to see if any more could have been done, Ardern said.

Ardern said the police were tireless and had been told up to 30 people had been involved in the operation

To Auckland, she said times are tough but we are all with you.

She said the Counter-Terrorism Legislation Bill will be passed by the end of the month, and she thanked National leader Judith Collins for her support to use urgency to pass the bill.

Ardern quoted the Imam of Christchurch's Al Noor mosque, saying we stand for peace and love, not hate.

Asked whether the law failed New Zealanders, Ardern said at every avenue was utilised and when it wasn't possible for him to be detained, heavy surveillance was used.

However, she said it was incredibly tough when it was a lone actor.

The man was released in July, and Ardern said every legal avenue was used to keep him detained. Police were constantly monitoring him and had grounds to arrest him for certain reasons.

She said it wasn't fair to make an assumption that the law change would have made a difference in this case.

Ardern was given a written update of the situation in late July, and on August 9 she met with officials to discuss further options to reduce any risk.

"This was a highly motivated individual who used a supermarket visit as a shield for an attack."

In late August, Ardern said officials including Coster had met to discuss expediting passage of the Counter Terrorism Legislation Bill within 48 hours of their discussion, and Justice Minister Kris Faafoi then contacted the select committee chair to discuss speeding up passage of the bill.

Was terrorist radicalised in NZ?

Asked on his radicalisation, Ardern said she didn't know how that occurred. However, she said 2016 was the first time officials saw the man publishing problematic content.

"That was yesterday, the same day the attack happened," Ardern said.

Successive Governments did not progress this work, we did, she said.

He was charged with objectionable material and possession of a knife, but it was no longer viable to keep him in prison for these things which is when police stepped in with heavy surveillance.

Asked whether there was an opportunity to appeal against any of the sentences, Coster emphasised all legal avenues were looked at.

Ardern said she didn't have any information on a court-ordered psychological assessment. However, she said she had been seeking information on whether the man could have been sectioned.

Coster said it was fair to say the man had been "uncooperative" to address his behaviour.

Nothing had occurred to give a legal ground to intervene in any other way that police did, Coster said.

Ardern yesterday described the 32-year-old man as a "lone wolf" attacker, under 24/7 police surveillance.

Known only as "S" for legal reasons, the terrorist attacker had been previously arrested for allegedly planning a knife attack.

Police remained on the scene of the New Lynn supermarket on Saturday morning. Photo / Dean Purcell

Ardern said information about the attacker covered by court suppression orders, but she believed it was in the public interest "to share as much as we can" when they were able to legally.

She said the individual had been on a Government watch list since 2016, and was known to have Isis-inspired views. However, she stressed his actions did not represent any ethnicity or community.

Countdown supermarkets opened at the later time of 10am after the terror attack in New Lynn yesterday. Photo / NZ Herald

"What happened today was despicable, it was hateful, it was wrong," Ardern said.

"It was carried out by an individual, not a faith, not a culture, not an ethnicity, but an individual person who was gripped by ideology that is not supported here by anyone or any community.

"He alone carries the responsibility for these acts. Let that be where the judgment falls."

Police Commissioner Andrew Coster addressed the media alongside Ardern on Friday. Photo / Stuff / Robert Kitchin

Speaking to media alongside Ardern yesterday, Police Commissioner Andrew Coster said the man was "closely watched by surveillance teams and a strategic tactical team" as he travelled from his home in Glen Eden to Countdown in New Lynn yesterday afternoon.

"I know this operation raises questions about whether the police could have done more," Coster said.

"The reality is when you are surveilling someone on a 24-hour basis it is not possible to be immediately next to them."

Coster said there was nothing to indicate before the attack that the man had travelled to New Lynn Countdown for anything other than a "routine shop".