A manhunt is under way after police confirmed the two people found dead in South Auckland were victims in a suspected double homicide.

Police said they would search through the night for the person or people they believed were responsible.

"At about 1.45pm, emergency services responded to reports of a woman unresponsive at an address on Gambare Place.

"Sadly, she was pronounced dead at the scene.

"During a search of the property police have located a man who was also pronounced deceased."

Detective Inspector Tofilau Faamanuia Va'aelua said the offender or offenders fled the scene prior to officers arriving.

"We know the community will be understandably alarmed by what has occurred, and we are doing everything we can to locate this person and hold them to account," Va'aelua said.

"While this appears to be an isolated incident at this stage, we are unable to rule anything out."

Police were now determining the exact circumstances of the incident, he said.

"This is an awful set of events and no doubt unsettling for everyone involved and the wider community."

Neighbours told RNZ the people living at the house had not been there for long.

Cordons are in place on Mahia Rd in Wattle Downs, with residents not able to enter while police conduct a scene examination.

Members of the public are advised to avoid the area.

A staff member at a bar in Manurewa's Southmall told The New Zealand Herald she saw "quite a few police" running past the venue towards the McDonald's carpark on the corner of Great South Rd and Weymouth Rd.

She said a customer told her they had seen "someone running around with a gun".

The Herald reports a body was lying covered in the middle of Gambare Place.

A resident of the street told the Herald the whole street was closed off as officers investigated incident.

"No cars are allowed, no children are playing outside today and the public has been asked to stop walking on the street and stay inside."

The incident prompted Te Haikura a Kiwa and Leabank Primary School to go into lockdown. Both have since lifted the restriction.

"We have come out of lockdown and all students, staff, and persons on-site are safely accounted for. Everyone did extremely well and responded to instructions," Leabank Principal Caroline McLeod posted on social media.

"A notice will be going out to parents/caregivers tonight to provide some more information on what has occurred today."