The 40-year-old was shot dead by a senior police officer inside Westfield Bondi Junction on Saturday afternoon, after setting upon several people inside the complex with a knife and triggering an evacuation.

Six people were killed, including four women and one man who died inside the centre, and another woman who died in hospital.

The infant has undergone surgery.

Many sheltered in locked stores while scores of others ran to the closest exit of the shopping centre, one of the biggest in Sydney.

Witnesses have described panic and confusion inside the centre as the seriousness of the situation became clear.

Warning: Some readers may find the following details of the attack, witness accounts and footage of the incident distressing.

Late last night, NSW Police Commissioner Karen Webb revealed that although the formal identification process has not been completed, police believe they know who the attacker is.

"We know a little bit about this person," she said.

"If it is the person we believe it is, we don't have fears for the person holding an ideation — in other words, that it's not a terrorism incident."

The Westfield — now a "very complex crime scene", according to Commissioner Webb — will remain closed on Sunday as authorities help with the removal of vehicles that remain in the car park.

Police investigating attacker:

The commissioner said the person was known to authorities and there were "elements" that indicate it was not a terror-related motive.

Police will now comb through his background, home, vehicle and associates to learn more about the man, but say they do not believe he was targeting any specific victim or victims.

Witnesses say the first signs of trouble came when they saw shoppers running.

Videos from inside the centre show the knife-wielding man was confronted by others who tried to stop him as he moved between levels.

Several graphic videos show attempts to perform CPR on the injured, as an evacuation alarm echoes through the otherwise empty complex.

The Australian Federal Police (AFP) is also assisting state police with the investigation.

AFP Commissioner Reece Kershaw said it was too early to determine a motive and it would be "Unhelpful to speculate".

Police inspector who shot attacked hailed a 'hero' 

Prime Minister Anthony Albanese said the devastating scenes were beyond words or understanding for most Australians.

"This was a horrific act of violence indiscriminately targeted at innocent people going about an ordinary Saturday, doing their shopping," he said.

Mr Albanese extended his deepest condolences to the families and loved ones of victims, while highlighting the courage and bravery on display at the scene.

"Staff for whom this should have been a normal shift, shoppers peacefully going about their lives, and yet for these Australians, their first instinct in the face of danger was to help someone else."

Commissioner Webb said the officer who shot the man dead was an inspector who had been "enormously courageous".

"She's doing well, under the circumstances," the commissioner said.

"She would need to be interviewed formally. So we just talked about that she's OK, her family is OK. She's got everything she needs for the time being."

Mr Albanese said the senior officer was a "hero".

"There is no doubt that she saved lives through her action," he said.

"It is a reminder that those people who wear a uniform, are people who rush to danger, not away from it."

Source | ABC