An officer being shot dead in Auckland today is the worst news that police or their families can get, Police Commissioner Andy Coster says.

"This is a shocking situation," Coster said.

"Our thoughts are with the officer's family and loved ones as well as the other officer and member of the public", he said.

It was devastating news and absolutely the worst thing for us to deal with, he said.

"This is a terrible day for. us. Thankfully we don't lose officers frequently."

Prime Minister Jacinda Ardern said the police officer's death was "devastating".

Officers were unarmed

The officers were not armed at the time, Coster said.

"It's far too early to speak to what would have made a difference in this situation."

Coster would not say whether the officer was male or female until notifications were made.

"It appears as though this situation escalated quickly, if not immediately". There was no pursuit

Coster was on his way to Auckland to offer support.

There are eight schools currently on lockdown, Coster understood.

"This violence was directed at police," Coster said.

He did not believe the public needed to be concerned.

Routine police stop

Coster said from the information he had it was a routine police stop and there was no indication it was going to be out of the ordinary

The second officer was in hospital as was a member of the public. The officer had serious injuries. The offender fled the scene.

The attending officers were shot, he said.

While the search was underway, police would be armed, Coster said.

The police organisation is in a state of shock, he said.

The officer who was injured had leg injuries, Coster said.

"We are not in a position to identify the offender at this stage" but police were seeking a person.

"There's a heavy policy presence in West Auckland at the moment" with some schools closed and armed offenders units on standby

He was confident police had done what was necessary to keep the public safe.

"This is a dynamic situation and I'm sure it will change through the afternoon."

A large investigation team and the armed offenders squad.

It was believed two people were in the car. The weapon was described as long-barrelled.

He could not say whether the offenders were still in the vehicle.

'I feel sick, I feel shattered' - colleague of killed officer

Police sources have told the Herald everyone was devastated by the shooting.

"This is the worst nightmare ..." said one.

Another said "I feel sick, I feel shattered.... someone came to work today to save the lives of others and they are going home in a box."

"This will be the first plaque on the (remembrance) wall since 2009.

"We've got to find this (offender)."

"We thought despite an increase in firearms on the streets we were holding out own... but we knew it was volatile.

"We took 60,000 guns off the streets in the buy back and then to have the first death in 11 years - a police Officer gunned down, gunned down and slaughtered.... it's absolutely awful."

PM on the officer's death

Ardern says the news of the police officer's death was "devastating".

"To lose a Police officer is to lose someone working for all of us, but also a family member, someone's loved one and friend. My condolences go to them and to their Police whanau," she said.

Police Minister Stuart Nash said he was "heartbroken for the family and colleagues of the officer who has died today".

"We want all our Police officers to get home safely at the end of every working day. This is a tragic day for our Police family.

"We have another officer injured by gun fire and a member of the public has also been injured by a fleeing offender. Our thoughts are with them.

"I have spoken to the Commissioner of Police this morning to ensure that he and his senior commanders have all the resources they need to respond. Police will provide further updates as they are able to.

"The officers' families and colleagues also need all the support they can get. This will take a toll on them in the days and weeks ahead.

"I want to thank those who were first on the scene to help and acknowledge the health professionals who worked to treat the officers.

"In the history of New Zealand policing since 1890, 22 officers have been shot and killed on duty, most recently Senior Constable Len Snee in Napier in 2009. Since 2002, 15 officers have been wounded by firearms.

"Massey has a strong community spirit and this will be frightening for the locals caught up in this. I urge members of the public to follow instructions from Police and to keep themselves safe," said Nash.

Earlier:

Two officers were shot and a member of the public was hit and injured by a vehicle after police performed a routine traffic stop on Reynella Drive in Massey.

St John confirmed three people have been taken to hospital. One of the police officers has died.

The Herald understands one of the shot officers was calling for help. He could be heard yelling that he had been shot and was bleeding.

Another of those hurt suffered serious injuries and the other is said to have moderate injuries.

The offender fled the scene in a vehicle and police have a large presence actively searching for the person.

Cordons are in place and schools in the immediate area have been advised to lockdown.

Police have advised all members of the public to avoid the Massey area, in particular the areas around Don Buck Road, Waimumu Road, Hewlitt Road and Triangle Road.

Elaine Taniela, who lives near Reynella Drive, was at home when she heard three distinctive sounds she now believes were gunshots.

"My dad was outside and heard them as well."

Taniela said her father's friend, who had been coming over to their house at the time, described harrowing scenes as he drove down Reynella Drive heading towards Triangle Rd.

"He was shaking telling us," she said.

"As he neared the first roundabout (near Gallony Avenue) he saw a cop on the ground.
"He said it looked like he was having a seizure. He was shaking."

It has been 11 years since a police officer was killed in the line of duty in New Zealand.

The last police officer to be killed by a criminal act was Senior Constable Len Snee, who was shot dead by gunman Jan Molenaar in Napier in May 2009.