Downtown Auckland remains closed in the aftermath of the shooting which left three dead, including the gunman.

Two civilians died after a gunman armed with a pump-action shotgun stormed a building undergoing renovations at 1 Queen St this morning.

The shooter has been identified as 24-year-old Matu Tangi Matua Reid. He was on home detention for domestic violence and had approval to travel to the building site.

Prime Minister Chris Hipkins said the whole nation was mourning at a 5pm press conference.

“The victims went to work this morning as they do every morning, but they won’t be coming home tonight,” he said.

Two police officers were shot at, Hipkins said, and his thoughts were with them.

“They are New Zealand heroes.”

STORY CONTINUES AFTER BLOG:

Hipkins said he had met with the Police Commissioner. He had confidence police would determine why and how the shooting happened.

“The trauma of this event will still be significant,” he said.

“Agencies will conduct their own investigations into what happened this morning. Corrections will do a full review into the offender’s management.”

The PM reassured Aucklanders and visitors to the city were safe ahead of the opening game of the Fifa Women’s World Cup at Eden Park.

“This is a standalone incident. People should feel safe while out and about in Auckland,” he said.

There would be a large police presence around the city tonight, Hipkins said.

“It is safe to go to the Fifa opening event. We would have preferred it to not have started this way.

“I will be going, it will be safe to go.”

He said the incident would be acknowledged at the opening game.

Police Armed Offenders Squad officers search a restaurant in Commercial Bay during an active shooter incident in Downtown Auckland. Photo / Supplied

In a statement, construction company LT McGuiness said the gunman was an employee of a subcontractor that had been working on the project.

“Today’s tragic event has been a huge shock to us all. Our thoughts are with the victims and their families, and all those impacted by the incident that occurred on our site this morning.”

Earlier, Police Commissioner Andrew Coster, speaking at a media briefing this afternoon, offered his condolences to the family and friends of colleagues and victims.

AOS and construction workers on the roof of the Deloitte building in Downtown Auckland. Photo / Supplied

Coster said his investigation team was working at pace to determine the cause of the shooting.

He said police were at the site within minutes of receiving multiple calls just after 7:20am.

The offender made his way up the site, and members of the public were evacuated whenever possible.

Police located the offender in a lift shaft. The offender fired at police, injuring an officer.

Coster said the officer will receive surgery today.

“This was a terrifying experience.”

Coster said it was a shocking and traumatic event for those who came to work and found themselves in the middle of an armed emergency.

The offender did not have a firearms licence. Coster confirmed the weapon fired by the offender was a shotgun.

Coster confirmed the offender was the subject of home detention. He wasn’t breaching conditions by going to the site.

He was known for his family violence history but said there was no history of showing prior risk.

“There has been previous search of his property, but never found him in possession of a firearm”

Stuart Cockburn, general manager of ambulance operations for St John, said they had assessed 10 patients and seven have been taken to hospital.

The Herald understands the gunman responsible, Reid, was serving a community-based sentence of home detention at the time of the shooting and was subject to electronic monitoring via an ankle bracelet tracker.

Police said at least one person had taken themselves to hospital with moderate injuries.

Witnesses have recounted seeing the gunman walk calmly through Britomart train station moments before he stormed the One Queen St building, which was being renovated.

Construction workers in the building have recalled the terrifying moment the shooter, armed with a pump action shotgun, came up the stairs yelling at them to go up to the roof or he would shoot them.

Workers told the Herald they began to leave the building when the fire alarm went off but it was only when people started running and shouting they realised it was not a drill.

Images show workers in high-vis vests crouching behind objects on the roof and in offices halfway up the building.

Workers shelter on the roof of a construction site as emergency services deal with the scene of an active shooter in Downtown Auckland. Photo / Hayden Woodward

One worker, who came across the gunman in the stairwell, went up towards the roof of the 21-storey building then hid on another floor of the building with a colleague before reaching the top of the tower.

“I’m shaken,” said the man who heard multiple gunshots while inside the building.

Another worker realised something was going on when he came across his distraught manager on the stairs who was screaming at him to go down.

Moments later he came across another manager who told them to go up.

“We went to 12, and other guys said go up, so then we went to 16 and stopped because no one knew [what was going on],” he told the Herald.

That’s when he heard the gunshots and saw a man drop to the concrete floor.

His colleagues were running around the floor looking for places to hide as gunshots continued to echo from the stairwell.

The man saw one colleague tying his vest around his head to stop the bleeding and came across a huge puddle of blood around the man when he went to help.

“It was around one-and-a-half litres of blood, no less,” he said.

The worker told police about the injured man as he went down the staircase, which was now spread with drops of blood.

”When I got outside I was just shaking, because I didn’t think [this would happen].

”Why he didn’t shoot me? I was last, and I walk slowly.”

An injured police officer is led away from an active shooter situation in Downtown Auckland. Photo / Tony Johnson

The Australian reported a group of workers barricaded themselves inside an office.

“We barricaded the door to the office we were sitting in and started hiding under the desk. It was daunting because the door was quite slim and someone could have pulled it off. Being young you don’t think of mortality too much but sitting there drove it in.”

They reported that there were around 100 workers on-site at the time and that colleagues saw the gunman in the stairwell.

“Everyone scattered,” he said.

“I saw a hard hat with blood spattered all over it. Then we ran behind one of these doors and found eight other people there, we could see the guy walking around with his gun. After that we ran back into the office and barricaded the door.”

A building worker said he thought it was possible the gunman entered the building for up to an hour before people knew he was there.

He and his co-workers scattered out of the building and headed towards the wharf when they realised there was a gunman inside.

“The cops were rushing in. But he was already at the top of the building… the gunman.”

The worker said there were security systems that required a pass to get into the building, so they were surprised the gunman was able to get in.

“Because for someone that knows how to get inside, like, he probably works on the site, too. He probably knew how to get in and where everyone’s gonna be in the morning.”

The worker said it was possible the shooter had been in the building since as early as 6am before the chaos unfolded.

“Everyone was in shock, some of our boys were still in the building and some were already outside.”

Armed police swarmed the area. Photo / Jason Oxenham

Earlier, Hipkins said police received a call about a man with a gun firing at people in a building on Lower Queen St at 7.23am.

Three minutes later the Eagle helicopter was dispatched and at 7.34am the first police officers arrived at the scene. Four minutes later the Armed Offenders Squad also arrived.

“The offender was armed with a pump action shotgun,” Hipkins said.

“He moved through the building site and discharged his firearm.

“Upon reaching the upper levels of the building the man contained himself in an elevator and police engaged with him.”

Shots were fired and he was found dead a short time later, he said.

Hipkins thanked the “brave men and women” of the New Zealand Police “who ran into fire from the gunman straight into harm’s way in order to save the lives of others”.

“These kinds of situations move fast and the actions of those who risk their lives to save others are nothing short of heroic.”

Police and Hipkins have reassured the country it was an isolated incident and there is no further threat.

There was no indication the shooter was politically or ideologically motivated.

Armed police and construction workers in Downtown Auckland as police deal with an active shooter. Photo / Jason Oxenham

The 24-year-old gunman was wearing an electronically monitored ankle bracelet and was on home detention at the time of the shooting, the Herald understands.

He had appeared for sentencing in the Auckland District Court earlier this year after admitting charges of impeding breathing, injuring with intent to injure, wilful damage, and male assaults female.

He was sentenced to five months’ home detention on the four charges when he appeared for sentence before Judge Stephen Bonnar KC on March 28.