A NSW Police Force employee has been shot dead in a double shooting outside the state's police headquarters in Sydney's west.
Fairfax Media has been told at least one gunman opened fire on a police IT worker outside the State Crime Command, which houses some of the state's top detectives, in Parramatta at 4.35pm on Friday.
Police said an officer then returned fire.
Police block off Charles Street in Parramatta where two people have been shot dead. Photo: James Brickwood
"It appears an officer has discharged his weapon, responding to a report that a person had been shot," a police spokesman said. "Two people have died at the scene."
Emergency services were called to the corner of Charles and Hassall streets after receiving reports that a man was shooting at people.
Witnesses reported seeing two bodies, at least one covered in blood, lying on the street.
Fairfax Media has confirmed one of the people shot dead is not a sworn officer but a civilian employee of NSW Police who works in information technology.
A police source has told Fairfax Media that there was increased "chatter" detected in the past week relating to a possible attack on the Parramatta headquarters.
The officer, who works at the State Crime Command headquarters, said that every officer had been ordered to wear their guns on them at all times this week, even while at their desks.
The building is home to the the homicide, drug, Middle Eastern organised crime and gangs squads.
It is understood police became aware of a plans for a possible attack on Parramatta headquarters 12 months ago.
A man called Nathan told 2GB Radio that he saw a man lying on the street surrounded by blood.
"I saw the guy dressed in black on the pavement with blood everywhere," he said.
Police cordoned off the area around Hassall and Charles streets.
A number of residential and commercial buildings in the area have been put into lock down.
Police said they would launch a full investigation into the incident.
A police spokesperson is expected to address the media soon.
