Armed police this afternoon stopped a car on Lincoln Rd after two police officers were shot - one dead - during a routine traffic stop this morning.
A witness said police stopped a black car on the overbridge in Massey. It is thought to have been spiked earlier.
A man was seen in the back of a police car.
Earlier, police stormed a house in West Auckland and arrested two men.
Shortly before 2.30pm police moved to the house on Rena Place in West Habour slowly behind their vehicle and then surrounded it.
A man living near Rena Place said armed police flew up Moire Rd and turned into Rena, some of them driving up over the grass.
One man was seen coming out of a house with his hands in the air.
He was arrested and a second man soon followed and was also arrested. The man said two women also came out from the house and we're seen talking to police.
It is not yet confirmed if the men are linked to today's shooting.
Neighbours are standing in the street watching and builders are on a roof at a new build across the road.
'Dedicated his career to keeping us safe'
Police Minister Stuart Nash said the officer who died was a man who "dedicated his career to keeping us safe".
"Over 10,000 men and woman have lost a valued colleagues," he said.
"What an absolute tragedy. What can you say," Nash said.
Police Commissioner Andrew Coster said this afternoon that an officer died after two were shot in Massey today. Shots were fired, officers were hit and a member of the public was hit and injured by a vehicle after police performed a routine traffic stop on Reynella Drive.
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.
It has been 11 years since a police officer was killed in the line of duty in New Zealand.
The last was Senior Constable Len Snee, who was shot dead by gunman Jan Molenaar in Napier in May 2009.
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 advise 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.
Terrified witness describes seeing officer on ground
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."
Taniela said her father's friend immediately stopped his car and tried to get out of the car.
"He wanted to help the cop. But the neighbours and another cop yelled out to him - telling to carry on driving."
As the man then got back into his car and drove off, he saw a second police officer "hunched over" another person he believed was also a police officer.
'Shocked and speechless': Local board chair
Henderson-Massey Local Board chairman and former Labour MP Chris Carter was unaware of the shooting when contacted by the Herald.
"On behalf of the community and for the families of the affected officers I'm really, really shocked and speechless. It is not the sort of thing you think will happen in New Zealand," he said.
Worried parent waits to collect son
A concerned parent is waiting to collect his child, whose west Auckland kindy is in lockdown.
Jordan is standing outside Reynella Drive in Massey, hoping to pick up his son from the kindergarten on the street.
He says he got a call from his partner that his son's kindy's in lockdown.
Jordan says he's trying to get his son and go home.
St John confirmed they had several ambulance units at the scene in Massey - after being called to the incident about 10.40am.
Three ambulance vehicles, one rapid response unit and three manager units were sent. The latter unit is usually sent to very serious incidents.
A woman at the St Paul's Catholic Church on Waimumu Rd said about 11.15am that she had seen two police cars zooming down towards Don Buck Road a few minutes earlier.
A police helicopter is also now hovering above the area.
"We were wondering what was happening," she said.
A police spokesperson confirmed officers are responding to an incident in Massey but would not comment further.
Flowers at the scene
People are leaving flowers at the scene of the shooting and Henderson police station.
One man who took his two young daughters to the scene at Reynella Dr with a bouquet of flowers said the girls were at school when it happened.
"We came to pay our respects for the fallen policeman and the girls wanted to give some flowers."
He said he didn't know the officers involved but the girls were put in lockdown at school so he explained to them what had happened.
"It's quite sad, you just don't expect this when you go to work."
He said he felt for the officers who are now having to deal with the aftermath of the fatal shooting.
"I guess it's hard for them because they have to deal with it".
The officers at the scene were clearly touched by the gesture. One female officer came up to the man and his daughters as they were leaving to thank them.
The flowers are now now sitting the police cordon while.officers continue to conduct a scene examination.
People have also left flowers at Henderson police station where flags are flying at half mast.