A teenager has been fatally stabbed overnight in Moerewa - the fifth homicide in New Zealand in a week.

Northland Police have launched a homicide inquiry after the 18-year-old, named as Krillan Koni Brown, was killed at a house in the Far North town, close to the Bay of Islands.

Police and ambulance were called to a Snowdon Ave address around 12.20am where Brown was found unresponsive.

Despite attempts to revive him, he died at the scene, police said in a statement. A number of young people had been at the address before he was killed.

A scene guard was in place with police remaining at the scene this morning. Inquiries were ongoing to locate the person responsible, police said.

Detective Senior Sergeant Mark Dalzell said investigators would like to speak to people who were at the Snowdon Ave property last night.

"There were a number of young people at a gathering at the address, and as part of our inquiries we would like to speak to anyone who was there who has not yet spoken to us," he says.

Anyone who was at the property last night is asked to contact police on 105, either online or over the phone, and quote job number P042477664.

They come on top of a month of mayhem in which a string of deadly attacks contrasted starkly with the relative calm of the Covid-19 lockdown.

The country had seen relatively few fatal, violent incidents during lockdown, which finished on April 27.

But since May 1 the Herald has counted 12 alleged murders - a deadly lurch forward after the country recorded its lowest homicide rate for 40 years in 2018.

That year, seven people were killed for every million in our country, for a total of 35 deaths. Last year's figures were skewed by the tragedy of March 15.

Violent deaths since May 1

May 1

Auckland: Solo mum

Tania Hadley dies after being stabbed, covered in petrol and set on fire. A man has been charged with murder.

May 11

Tokoroa: A woman aged 28 is charged with murder after a man is found dead at a house on Moa Place.

May 13

Auckland: The body of Angela Smith is found in her Henderson flat. Two men, 51 and 58, are charged with murder two weeks later.

May 16

Te Anau: Police are called to a motel where they find the body of Shirley Reedy. A man, 52, is charged with murder a short time later.

Three women were killed in the fortnight following lockdown; from left Tania Hadley, Angela Joy Smith and Shirley Reedy. (Photos / Supplied)

May 17

Otaki: Police charge a 33-year-old with murder after a man in his 50s dies after being injured at Mill Rd.

May 20

Rotorua: Police charge a man, 59, with murder after the death of a man in Owhata.

May 26

Auckland: Police launch a homicide inquiry after the death of a girl, aged 1, in Clover Park.

June 1

Auckland: The body of Mongrel Mob member Clifford Umuhuri is found near Auckland City Hospital after a shooting in St Johns.

June 1

East Cape: Police arrest a man, 56, after the death of a man in his 50s at Waihau Bay, north of Opotiki.

June 4

Auckland: One man killed and another injured. A 37-year-old man has appeared in court charged with murder and grievous bodily harm.

June 5

Hamilton: A person is killed at 8 Slim St in Hamilton. Police are seeking the public's help finding the killer and have asked for anyone seeing people or vehicles leaving the house between 5.30pm and 5.45pm to make contact.

June 7

Moerewa: Man fatally stabbed. Police and ambulance called about 12.20am and found an 18-year-old unresponsive. Despite attempts to revive him, he died at the Snowden Ave scene.