One person has died and another is injured following an incident in Northcote this evening.

Police were called to an address on Akoranga Dr around 5.30pm following reports of someone being assaulted.

When they arrived, they found one person with critical injuries. The person has since died. Another person sustained injuries and has been taken to hospital.

Police have taken one person into custody.

"While this incident will be unsettling for the community initial indications suggest the parties involved in the incident were known to each other," police said in a statement.

"Police are currently speaking with witnesses and working to understand the circumstances of this incident."

They asked anyone who has information that may help the investigation to call police on 105.

Information can also be shared anonymously via Crimestoppers on 0800 555 111.

Earlier, a man was heard screaming for help. A witness told the Herald at least 10 police cars were at the scene.

"There was at least three ambulances earlier, but there are two here now and a manager."

Te Aroha Devon was walking home from the nearby Auckland University of Technology campus when she someone screaming for help.

"There was a gentleman across the road in the house, on the second floor who was yelling for help," she said.

"He was yelling "Help, help, help me'. He would not say what was wrong," she said.

"There was an older gentleman on the ground outside looking up at him, pointing at him, trying to talk to him. I couldn't hear what he was saying."

"I think he was signalling him to hold on and to wait."

Another man in a car outside of the residence rushed out to attend to the man, minutes before the first police car arrived at the house, she said.

Ambulances followed and officers entered the house.

Northcote resident Rick Mozessohn, who posted a photo of the scene on social media, said he saw between 10 and 15 police cars, two or three ambulances and one or two fire engines outside the house at 40 Akoranga Drive at about 7pm.

"There's quite a few people standing round. It must be something specifically in that house," he said.

Fire and emergency New Zealand were also in attendance but have since left.