A 39-year-old man is in a critical condition and undergoing surgery in Royal Perth Hospital following a mass stabbing in WA's north, in which an armed man was shot dead by police officers.

Officers were called to the South Hedland Square shopping centre just before 10:00am on Friday, following reports of an armed offender.

Police said two officers confronted the man, who was armed with a large knife, and discharged their tasers before one officer fired several shots.

Seven people were stabbed during the attack, including the 39-year-old man who was flown to Royal Perth Hospital Friday night.

Five people — three women, aged 24 to 37, and two men, aged 19 and 37 —were treated at the Hedland Health Campus and released from hospital.

Another man, aged 20, received a minor injury which did not require medical treatment.

Detectives from the Major Crime Squad are investigating the incident, overseen by a detective inspector from the Professional Standards division.

Friday, WA Police Commissioner Chris Dawson said he believed the deceased man was employed as a fly-in, fly-out worker.

Pilbara District Superintendent Kim Massam confirmed the deceased 34-year-old man was from Perth and worked in the Pilbara, but could not provide any further details due to the ongoing investigation.

"This is a tragic time for our community and a number of people witnessed something that they would never normally see in their lifetime," Superintendent Massam said.

"It's very much about how we as a community come back together, how we recover from this tragic situation, how we move forward in what is a very, very sad time."

The welfare of the two officers involved was of the "greatest concern" to police, Superintendent Massam added, while extending his condolences to the deceased man's family.

"I have heartfelt sorrow for you and your family and I say that on behalf of [all] Western Australian police," he said.

Commissioner seeks to reassure town

The Port Hedland Commissioner, Fred Reibeling, said the incident had made "a significant impact" on the town, which has a population of only 16,000 residents.

"We've had seven individual victims …  almost everyone knows someone who was directly affected by this," Commissioner Riebeling said.

He said the focus would now be on the community pulling together.

"To move on, support those people who have been directly affected — and they will have, I think, some significant issues other than scars to deal with," he said.

In a statement published on Facebook, Senior Sergeant Jeremy Marklew, officer in charge of the South Hedland Police Station, urged the community to be "courteous to all our shopping centre staff" after an "extremely long and traumatic day".

"Thanks again to everyone in the community who has messaged, emailed, and called us at the police station offering your support, it's sincerely appreciated from all the police here in Hedland and particularly myself," Senior Sergeant Marklew said.

"Our officers involved in the incident are 'OK', and we're doing everything we can to support them and their welfare, after their heroic duties yesterday."

Witness praises police actions

About 60 people witnessed the attack at the shopping centre, which reopened to customers Saturday morning.

Witness Peter Carter said he saw the man running, and police "chasing him with tasers" moments before the shooting.

"[That] policeman said "stop, drop, stop, drop" so many times — he had the best opportunity to stop, drop that knife," Mr Carter said.

"The security guards and police officers, they did a superb job, a wonderful job.

"You couldn't [fault] the way they handled the situation. It could have been a lot worse and they did it very, very well.

"You know, I feel sorry for the gentleman, his family, his friends … someone's passed away. Someone has lost their life.

"But at the end of the day, public safety is number one, and the police officers do the best they can."