A woman making her way home from work has been stabbed to death in what police called a "horrific, traumatic and random attack" in Christchurch. 

Canterbury District Commander Superintendent John Price confirmed a 37-year-old man had been charged with murder after the death of the woman. 

He will appear in court tomorrow. 

The victim, in her 50s, was not known to the offender. 

This was a horrific, traumatic and random attack on an innocent person who was simply making her way home from work, he said. 

The suspect is known to police. 

Price said police's thoughts were with the grieving family of the victim who were dealing with loss of partner, mother, friend and a colleague. 

At this stage, police would not release further details of the victim until all next of kin were notified. 

The traumatic, senseless act would have a huge impact on the community as a whole and right across New Zealand, he said. 

"I want to reinforce that this was an isolated incident and we are not seeking anyone else." 

Price also wanted to reassure residents of their presence in the area as they conduct a scene examination and look to speak to witnesses. He also called for anyone who saw anything, or anyone with CCTV footage, to come forward. 

"No-one deserves this." 

The knife has been found at the scene. 

Emergency services were called to Cheyenne St at 4.20pm yesterday after reports a woman had been stabbed in the street, he said. 

Staff arrived soon afterwards and gave assistance to woman who had been critically injured. 

"She sadly died at the scene." 

The man was found nearby by police and taken into custody. 

A second man was taken into custody but was later found to be a family member of the man and was released. 

The woman had caught a bus and was walking from the bus stop when the attack happened. 

The brother of the suspect turned up shortly after the incident occurred. 

Other agencies will be involved in the investigation, Price said, saying they want to get a total picture over the motive, means and manner. 

The community, and the family, "need to understand the why" given the random nature of the horrific attack. 

Police shooting in Kaiapoi 

Price then spoke about a police shooting in Kaiapoi last night. 

A man was allegedly threatening members of the public with a metal bar and knife. 

He attacked a police car with the metal bar when officers arrived. 

He was not cooperative with police, and tactical options including taser, OC spray and communication were deployed multiple times, Price said. 

But they had no effect on the man or his behaviour. 

He then went into a private residential driveway and police kept talking to him. 

After a further period of negotiation, police fired multiple shots, injuring the man. 

Police gave medical assistance to the man before he was rushed to hospital. He is still there in a serious but stable condition. Surgery was completed this morning. 

Price urged witnesses to come forward. 

"If you have any CCTV footage or cellphone footage, police contact police on 105." 

Officers are still getting support, "as this will have a huge impact on them and their whānau". 

"This isn't the outcome anyone wanted to happen." 

The man's family has been notified and are being supported. 

His identity cannot be revealed at this stage. The IPCA has been notified, while a police investigation and a critical incident inquiry is also under way. 

Price did not know how many officers fired shots. 

It unfolded over 15 to 20 minutes, from when police first came across the man – their vehicle was attacked – before negotiation, tactical options, before the man had "advanced on police and they have used firearms at that stage". 

He was struck in the abdomen, chest and limbs. 

The Kaiapoi scene, showing a police car with a smashed window. Photo / Kurt Bayer 

The individual was known to police, Price confirmed. 

"The last thing any police officer wants to do is to have to use firearms." 

Price stressed the two incidents were not connected. 

Earlier reports: 

"On arrival, a woman was located critically injured," Price said last night about the Cheyenne St attack. 

"Medical assistance was immediately provided; however, she died at the scene a short time later." 

Price said police took two men into custody nearby. 

Inquiries were ongoing "to establish exactly what has taken place". 

He said the initial calls to emergency teams were reports of a woman being stabbed. 

A resident said the Cheyenne St footpath appeared to be cordoned off with tape and flashing police car lights were visible. 

He said he wasn't home at the time of the incident, but when he returned there was a fire engine and at least one ambulance on the scene. 

"It's quite chilling really, if anything like that happens in your city or where you live," the resident said. 

Cordons have been put in place in the area and police ask motorists and pedestrians to follow directions given by emergency services staff. 

"Anyone who was in the Cheyenne St area around the time the woman was injured and may have information which could assist police is asked to get in touch via 105 and quote event number P051030807," Superintendent Price said. 

Police were also called to an incident in Kaiapoi, north of Christchurch, last night. 

They were alerted to a report of a man allegedly threatening a member of the public with a metal bar and a knife on Williams St near Ohoka Rd about 7.20pm. 

Price said when police arrived, the man attacked their vehicle with the metal bar. The man made his way to Peraki St where police unsuccessfully tried using a Taser and pepper spray on him. 

Police then fired multiple shots, critically injuring him, Price said. 

Officers provided immediate first aid to the man until paramedics arrived and he was taken to Christchurch Hospital, where he remains. 

"We understand this will be a shock to the Kaiapoi community and we want to reassure them that there is no ongoing risk," Price said. 

The Independent Police Conduct Authority will be notified and a Critical Incident Investigation is underway, as is standard practice.