Amy Scott single-handedly confronted the attacker, now identified by police as Joel Cauchi, as he roamed through Westfield Bondi Junction shopping centre having knifed several people.

Inspector Scott pursued Cauchi, and eventually came face-to-face with him on the fifth floor of the complex.

Witnesses said she shouted for him to "put it down" and then, as he lunged at her with the blade, she shot and killed him.

The officer conducted CPR on the 40-year-old until the paramedics arrived but he could not be revived.

Waverley mayor Paula Masselos told Sky News: "Even [after she shot the attacker], she immediately began applying CPR - that just shows you the dedication of the person and her incredible act of heroism - even then her main concern was for someone who had fallen."

Ms Scott, 39, has 19 years of experience in the police and is attached to the Eastern Suburbs Police Area Command.

She had been checking liquor licences at nearby hotels when the attack started and was praised for her heroic actions and bravery after she "ran towards danger".

New South Wales (NSW) premier Chris Minns said: "Of course, inspector Amy Scott, who ran towards danger, showed professionalism and bravery and without a shadow of a doubt, saved many, many lives in the last 24 hours."

Ms Scott was the first emergency responder on the scene.

Prime Minister Anthony Albanese said she was "certainly a hero" whose actions had saved many more lives.

"The wonderful inspector who ran into danger by herself and removed the threat that was there to others, without thinking about the risks to herself," he added.

Speaking to Sky News Australia, NSW police minister Yasmin Catley said she met with Ms Scott after the attack lauding her "humble" nature.

"When I met Amy last night... we talked about her going straight into police mode, everything she has been taught during her career and how instinctive it was," Ms Cately said.

"When I said to her 'thank you for your courage' she said 'it was not just me, the bystanders around me were so helpful'."

"[She was] so humble, it's just typical of a NSW police officer," she added.

Footage shows one bystander confronting Cauchi on an escalator, fending him off with what appears to be a bollard.

Police said Cauchi suffered from unspecified mental health issues and investigators are not treating the attack as terrorism-related, and have spoken to Cauchi's family.

Six killed in stabbings

Six people, five women and one man, aged between 20 and 55, were killed in the attack and 12 others remain in hospital including a baby.

New mum Ashlee Good was named as one of the victims.

The 38-year-old was reported to have passed her baby to two men after she was injured.

"I was holding the baby. It looked pretty bad," one of the men told 9News.

His brother added: "He helped with holding the baby and trying to compress the baby and same with the mother."

Ms Good's family said that after hours of surgery, the baby was doing well.

Dawn Singleton, 25, was also killed according to media reports in Australia.

A third victim was named as Faraz Tahir, 30, by the Australian Pakistani National Association.

It described him as "courageous" and said he was a Pakistani national who had moved to Australia for work.

The fourth victim is 47-year-old Jade Young, an architect.

The fifth victim of the attack was named as 55-year-old Pikria Darchia, who - according to her LinkedIn profile - worked in Tbilisi, Georgia, as a designer from 2003 to 2013 and described herself as an artist.

Police said another victim was from abroad and did not have family in Australia. They added officers were attempting to contact their family.

The Australian flag will be flown at half-mast on 15 April from all government-linked buildings to honour and mourn the victims of the attack.