A man has been shot dead by police after allegedly threatening officers with a large kitchen knife in a Sydney police station foyer.
A sergeant with 24 years' experience fired the single, fatal shot following a short confrontation with the man inside Quakers Hill police station just before 10.40am on Tuesday.
Homicide detectives have launched a critical incident investigation into the incident, which police say is not believed to be terrorism-related.
A member of the public was in the foyer and other officers were inside the police station during the brief confrontation between the man and the officer.
"At this stage we have been unable to identify the man, we have no idea of the motive for him coming to the police station," Assistant Commissioner Denis Clifford told reporters at the scene.
A large knife, believed to be a kitchen knife, was found inside the police station.
"There was a shot fired by the sergeant, it struck the man, he was rendered assistance but passed away a short time later," Mr Clifford said.
He would not say where the man, believed to be in his 40s, was shot. A CareFlight ambulance and paramedics responded to the shooting but efforts to revive him were unsuccessful.
"I've spoken to a number of officers in there and the officer who fired the shot is very distressed as you could understand," Mr Clifford said.
"But I can say that no police have been injured which is great." Lalor Road and the Quakers Hill police station remain cordoned off.
Nearby homes and a childcare centre opposite the police station were locked down in the aftermath of the shooting, but people were allowed to leave their homes by early afternoon.
Parents of children at the childcare centre were notified of the incident and are now being allowed to pick up their children.
Neighbour Brenda Dries said the area was a quiet neighbourhood where people felt safe living near the police station.
"It's good having the police station there ... they're very good, they're very good to us," she told AAP.
The ex-correctional officer said she wasn't concerned for her safety but said her young adult granddaughter, who was at her home when the incident unfolded, was left feeling "quite stressed".
