Six people have been killed in a stabbing attack at a Sydney shopping centre where a man was shot dead by a senior police officer as hundreds fled the scene.
Four women and a man died at the scene at Westfield Bondi Junction in the city's eastern suburbs, and another woman later died in hospital.
Eight other people were hospitalised, including a nine-month-old baby who was undergoing surgery on Saturday night.
A nearby NSW Police inspector entered the centre, catching up with the man on level five as people fleeing gave directions.
"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.
Police were confident there was no ongoing risk and the attacker, believed to be a 40-year-old man, acted alone, NSW Police Commissioner Karen Webb later 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," she said.
The man was seen on CCTV entering the centre about 3.10pm, leaving, and then returning a short time later, when he attacked nine people, Mr Cooke said.
"Things are very, very raw at this stage and we are in the very early stages of investigations," Mr Cooke said.
Prime Minister Anthony Albanese said the incident was a horrific act of indiscriminate violence and extended condolences to those grieving and injured.
But the response of emergency services and others at the scene whose first instinct was to help others illustrated the nation's humanity and heroism, he said.
"That is what we hold onto tonight as Australians, that is confirmation of who we are. Brave, strong, and together."
Australian Federal Police Commissioner Reece Kershaw said it was too early to determine if the incident was terror-related but said ASIO and other agencies were involved in briefings and the AFP was providing any required assistance.
Like all shootings involving NSW Police the investigation will be monitored by the Law Enforcement Conduct Commission.
Multiple posts on social media showed crowds of people outside the shopping centre as it was placed into lockdown.
One man told ABC: "They just said run, run, run someone's been stabbed."
"(The attacker) was walking really calmly like he was having an ice cream in a park. And then he went up the escalators ... and probably within about a minute we heard three gunshots," he said.
Another witness told 7News the responding inspector had saved lives.
"If she didn't shoot he would have kept going and I don't know how many more he would have done," he said.
Other witnesses told of grabbing their children and running from the centre along with hundreds of other people.
Federal Oppostion Leader Peter Dutton said Australians would be in shock over the "tragic and terrifying events" and grieving for those who died.
He thanked the police officers and first responders who acted quickly to save others.
NSW Premier Chris Minns said he was horrified to hear of the attack and was making immediate arrangements to return to Sydney.
"I want to thank NSW Police, emergency services and first responders and the community for their bravery in the face of this shocking incident," the premier said.
