A “beautiful” mother who threw her bleeding baby to strangers is one of six people killed by a male stabber who randomly knifed shoppers at an eastern Sydney mall.

Osteopath Dr Ashlee Good, 38, was fatally stabbed when the man wearing a Kangaroos NRL jersey attacked strangers at Westfield Bondi Junction on Saturday afternoon.

Wielding a knife, the 40-year-old indiscriminately attacked shoppers in a shocking mass stabbing that Prime Minister Anthony Albanese said was a horrific act of violence.

Four women and a man died at the scene and Good died later in hospital on Saturday night.

Her nine-month-old baby girl, who was undergoing surgery on Saturday night, was among eight others hospitalised with injuries.

‘Hero’ female officer

Footage from inside the complex showed people fleeing as a man chased them through the centre.

One member of the public was seen in a stand-off with the attacker, holding a bollard at the top of an escalator and confronting the armed man as he approached.

A member of the public wields a bollard to confront the stabber. Photo: AnnaMcGovernUK (Twitter)

A lone female police officer who responded to the emergency and shot the killer has been hailed as a hero for stopping him before he could take any more lives.

The Daily Mail has identified the NSW Police Inspector as Amy Scott. She entered the mall and tracked the man to the fifth floor, seeking information from people who were fleeing the terrifying scene.

“She confronted the offender … as she continued to walk quickly behind him to catch up with him, he turned, faced her, (and) raised a knife,” NSW Police assistant commissioner Tony Cooke told reporters on Saturday.

“She discharged a firearm and that person is now deceased,” he said.

One unnamed witness told the ABC the man was “on a rampage” and would have kept stabbing people if he had not been shot.

“He just started floating towards us and all I heard was ‘put it down’ and then she (Scott) shot him,” he told ABC News.

“Then she walked over and gave him CPR. He had a big blade on him — she chucked the knife away. He looked like he was on a killing spree.”

The lone police officer after shooting the alleged stabber. Photo: Twitter

No motive or ideology has been determined yet, but police said the mass killing was not a terrorism incident.

The perpetrator, who has not been publicly named, was acting alone and there was no ongoing threat, police said.

“We know a little bit about this person … if in fact it is the person we believe it is, we don’t have fears for that person holding an ideation, in other words that it’s not a terrorism incident,” said NSW Police Commissioner Karen Webb.

The centre is closed and will be an active crime scene for days.

The man wearing an NRL jersey climbs an escalator.

‘Prime of her life’

Sky News reporter Laura Jayes, who was reporting from the scene, named the first victim whom she knew from the local area.

Jayes said Good was a “beautiful woman” in the prime of her life.

“She has a beautiful circle of friends, she was an incredible athlete and she had the world at her feet,” said Jayes.

“Her family are on their way rushing here now, so many family and friends wanted to be at the hospital this afternoon, they had to take turns going in and out of the waiting room.

“They both (Good and her baby) went into surgery, her husband not knowing if either had survived and now the worst possible news.

“I just can’t really get my head around it. It’s just so cruel.”

Ash Good was loving being a mother and was in the prime of her life. Photo: Instagram

Just hours earlier, Good had posted a carefree and casual photo to Instagram, holding her daughter on her hip. She also posted a short video clip of the infant in a car seat to the tune My Girl.

Two brothers told Nine News they tried to stem the baby’s bleeding with clothes from a store after the badly injured mother came over and “threw” the baby at them.

“The baby got stabbed and, yeah, the mum got stabbed,” one of the men said.

“The mum came over with the baby and threw it at me. I just helped by holding the baby… and trying to compress the baby.

“(It was) very bad… a lot of the blood on the floor… hope the baby’s alright.”

NSW Premier Chris Minns, who was waiting for a flight back from Tokyo, said it was a truly shocking day in the state’s history.

“I can understand that people will be grieving and very angry for the next few days,” Minns told Sydney radio 2GB on Saturday.

“It’s literally everyone’s worst nightmare … a wicked and a violent crime,” he said.

Prime Minister Anthony Albanese praised the actions of the officer who responded alone as hundreds of shoppers fled the scene.

“She is certainly a hero, there is no doubt she saved lives through her actions,” Albanese said on Saturday.

Tweet from @AlboMP

Federal Opposition leader Peter Dutton said there was heroism amongst the horror.

“We thank everyday Australians who helped each other get to safety and those who provided comfort to others in distress,” he said on social media.

King Charles said in a statement overnight that he and Queen Camilla were “utterly shocked and horrified to hear of the tragic stabbing incident in Bondi”.

The royal couple praised the “bravery of the first responders and emergency services”.

Pope Francis also expressed his sadness at the “senseless tragedy” and offered his “spiritual closeness” to all those affected.

Like all shootings involving NSW Police the investigation will be overseen by the Law Enforcement Conduct Commission.

Webb said the inspector was doing well under the circumstances and will be interviewed on Sunday.

“She showed enormous courage and bravery,” Webb said, adding other responding police, civilians and staff at the centre had too.

“It was an awful situation … but it could have been much worse,” she said.

-with AAP