New Zealand police say gunman dead after killing two in attack on Auckland CBD construction site

The 24-year-old gunman who killed two people in an attack in Auckland's CBD did not have a gun licence and had a history of family violence, police say.

Police said six people were injured and three people — including the gunman — are dead, after he repeatedly fired shots at a construction site around 7:30am (local time).

Police Commissioner Andrew Coster said the shooter was cornered about 30 minutes later inside the building at the bottom of Queen Street.

"Our armed offender squad, supported by the special tactics group, located the offender inside a lift shaft where he had barricaded himself, and attempted to engage him, having secured the floors above and below," he said.

"The offender fired at police and injured an officer. Shots were exchanged and the offender was later found deceased."

Commissioner Coster confirmed two people were found dead on the lower levels of the building site.

He said the injured police officer was in a stable condition in hospital and is expected to undergo surgery.

Five civilians have moderate to serious injuries, he said, though "that number could be higher as people may have presented at the hospital in the last hour".

"We believe the firearm is a shotgun, so not prohibited, however the individual does not have a firearms licence so he should not have possessed that," he said.

"I can confirm that the offender is the subject of a sentence of home detention.

"He had an exemption to work at the site and so there is no indication at this stage of a breach of those conditions."

Commissioner Coster said the motivation for the attack was not clear.

"We understand he has worked at the construction site and believe the reason for his presence at the site this morning was connected with that work," he said.

"There are some indications of mental health history but I don't have the details.

"The individual is known for, primarily, family violence history."

Earlier on Thursday morning, New Zealand's Prime Minister Chris Hipkins reassured the public that the shooting was an isolated incident.

"There is no identified political or ideological motivation for the shooting and therefore no national security risk," he said.

"This appears to be the actions of one individual.

"Aucklanders and those watching around the world can be assured that the police have neutralised the threat and that they are not seeking anybody else in relation to the incident."

He said he could not confirm media reports that the gunman was wearing an electronic monitoring bracelet.

A heavy police presence, including armed officers and helicopters, responded to the incident.

"These kinds of situations move fast and the actions of those who risk their lives to save others are nothing short of heroic," Mr Hipkins said.

"I also want to acknowledge the ambulance first responders who were there quickly on the scene this morning.

"This is still an ongoing police operation and I have got limited further information that I can provide at this time."

Australian Prime Minister Anthony Albanese, who is to visit Wellington next week, offered condolences.

"I've been in contact with with Chris this morning … it is very sad indeed to see another dreadful shooting with fatalities," he said.

The mayor of Auckland, Wayne Brown, said the city had "never experienced anything like this".

"I'm shocked and saddened," he said.

"It's tragic and distressing for all Auckland ... we all send out our condolences to those who have been affected by this."

Locals reported hearing gunshots at about 8am, with media broadcasting footage of workers at the building site hiding behind packs of pre-mix cement under police supervision.

Truck driver Christina Tuala was near an inner-city building, closing up her truck after a making a delivery when the event unfolded.

"We had heard gunshots and people just running out the building," she said.

"We got escorted across the road and we could see people on the 13th and 14th level [of the building] cowering behind concrete boulders in there."

"And we saw one dude laying down on his side the whole time, so we weren't sure if he was hurt or not."

Ferry services, which use a nearby terminal to operate, have been cancelled.

The incident has taken place as Auckland prepares to host the opening game of the Women's World Cup later on Thursday.

The FIFA Fan Festival is nearby, with former NZ international Maia Jackson telling the NZ Herald she was nearby.

"It's pretty scary actually. So they pushed us to the back ... and we're just trying to keep sane," she said.

"There's lots of security and lots of uncertainty."

Mr Hipkins said there would be no change to the tournament schedule, following conversations with FIFA officials, with NZ set to play Norway in the opening match at Eden Park.

Soccer teams from New Zealand, Norway, Italy, the US, Vietnam and Portugal were known to be in the city when the shooting occurred.

A statement from football's governing body FIFA said it was supporting teams in the vicinity of the incident.

"FIFA has been informed that this was an isolated incident that was not related to football operations and the opening match at Eden Park will proceed as planned," the statement said.

ABC/Wires