Five people have been killed and an attacker has been shot dead after multiple people were stabbed at Westfield Bondi Junction shopping centre in Sydney's east.
NSW Police Assistant Commissioner Tony Cooke said the man walked into the centre at about 3.10pm and returned 10 minutes later at 3.20pm.
"As he moved through the centre, he engaged with about nine people," Cooke said.
"It is clear that during that engagement he caused harm to those people, we believe, by stabbing them with a weapon he was carrying.
READ MORE: Witnesses describe helping mother after stabbing attack
"Very clearly a range of reports were made of the incident, police attended promptly.
"A single unit officer, (an) inspector of police, was nearby, attended, went into the centre directed by a range of people.
"She confronted the offender, who had moved by this stage to level five as she continued to walk quickly behind him to catch up with him.
"He turned, faced her, raised a knife, she discharged a firearm and that person is now deceased."
Video obtained by 9News appears to show a man wearing a rugby league jersey holding a knife as shoppers flee.
Heavily armed police entered the centre as crowds of shoppers were ushered outside.
A Westfield spokesperson confirmed a critical incident has occurred at the centre this afternoon.
"The safety and security of our customers, business partners and people is our highest priority.
"Our team is providing full support to emergency services following the incident.
"At the direction of police, we are asking the public to avoid the area at this time."
NSW Ambulance said at least the injured had been taken to various hospitals.
"Multiple ambulance crews have responded to the incident, including medical teams with doctors onboard," it said in a statement.
"They have transported multiple patients to hospital, including two people to St Vincent's Hospital, one person to Sydney Children's Hospital, one patient to St George Hospital, one to Royal North Shore and two to Royal Prince Alfred."
Another ambulance went to Prince of Wales hospital.
Witnesses describe helping mother and baby
Two brothers have described how they helped a mother and her baby, both of whom had been stabbed.
"The baby got stabbed," one of the men told 9News.
"The mum got stabbed and the mum came over with the baby and threw it at me and (I) was holding the baby."
The man said he believed the baby would survive its injuries.
The husband of one of the injured told 9News he was relieved to see his wife at St Vincent's Hospital.
"We didn't know what had happened," he said.
"She just got a little, they said, stab in the top right-hand corner of her back.
"She thought she got punched and then she touched herself and there was blood.
"But apart from that, she's okay, she's alive and that's all that matters."
The man said once he saw his wife, the "stress was over".
"No one could tell you anything when we were there," he said.
"It was terrible but she's good now."
Earlier, a grocery shop worker at the shopping centre told 9News he was let out of the shopping centre just after 4.30pm.
"My girlfriend called me, she said that her mum works upstairs, level three and she said, 'Look, please be careful, there's a shooting,'" he said.
"I couldn't hear her well, so I came outside. I just started hearing a bunch of (shots).
"My reaction was to basically put all the customers inside (and) close the door of the shop."
What we know so far
- Multiple people have been stabbed at Westfield shopping centre at Bondi Junction in Sydney's eastern suburbs.
- NSW Police have declared a "critical incident' and say they shot a man just before 4pm today.
- Video appears to show a man wearing a rugby league jersey holding a knife as shoppers flee.
- Mobile phone footage shows crowds within stairwells, with other shoppers saying they rushed to the car park.
- Multiple people have been rushed to hospitals around the city, with a baby and a mother among those reported to be injured.
More to come.