A 52-year-old man has been charged with murder and wounding with intent to cause grievous bodily harm following an incident in Ilam Rd, Christchurch.

A 52-year-old man has been charged with murder after allegedly stabbing his ex-partner outside her workplace in Christchurch.

Police were called to Ilam Rd at 7.50pm after a 28-year-old woman and her 31-year-old partner were allegedly stabbed by a man who then used the knife on himself.

Stuff understands the woman had just left her workplace and was with her partner when the couple were stabbed by her ex-partner.

SAM SHERWOOD/STUFF A vehicle is being examined as part of the police investigation into an incident that left a woman dead and two men fighting for their lives.

The woman died of her wounds, and the two men were critically injured.

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Ilam Lifecare manager Maurice David confirmed the woman worked at the retirement home.

GEORGE HEARD/STUFF Cordons were placed on Ilam Rd.

"My main priority is dealing with our staff and making sure they are OK.

"My heart goes out to her family."

Detective Senior Sergeant Scott Anderson said the two men remained in hospital on Sunday in serious, but stable conditions.

GOOGLE Ilam Rd is expected to remain cordoned off on Sunday.

Anderson said the 52-year-old had been charged with murder and wounding with intent to cause grievous bodily harm. He said the stabbing was a "domestic incident".

"Although the investigation is still in its early days those involved were known to each other and police are not seeking anyone else in relation to the incident."

Several cordons are in place around the scene, which is between the cross streets of Kirkwood Ave and Riccarton Rd. A scene guard was set up on Ilam Rd on Saturday night and remained in place on Sunday. A blue tarpaulin covered the ground at the corner of Ilam Rd and Hanrahan St.

GEORGE HEARD/STUFF A cordon remained in place at the scene overnight.

A reporter at the scene said police were examining a white Toyota Corolla, parked inside the cordon with its boot open.

The cordon, expected to remain in place throughout Sunday, is about 250 metres long.

Tom Averill, who lives on Kirkwood Ave, said he and a friend were in an Uber driving past Ilam Rd about 7.45pm on Saturday.

GEORGE HEARD/STUFF A woman has been killed and two people are in a critical condition after a stabbing incident in Ilam Rd, Christchurch.

Averill saw two people run across Ilam Rd, followed by a third person shortly after. His friend heard "a massive scream", which sounded like it came from a woman, he said.

"It was definitely abnormal."

Six people were stabbed in four separate incidents on Saturday night. As well as the three in Christchurch, a homicide investigation is also under way in Moerewa after a 57-year-old man died. A woman is helping police with inquiries. Police say those involved were known to each other.

A man in his 40s was seriously injured in Hawke's Bay and remains in Hawke's Bay Hospital's intensive care unit in a critical condition, a spokeswoman said.

And an injured man took himself to hospital in Tauranga in the Bay of Plenty shortly after 3pm on Saturday after another incident.