Australian police probe terror links after 15-year-old shoots dead worker outside headquarters

Authorities have closed the streets around the New South Wales police headquarters in Sydney

Australian police are investigating the shooting (Getty)

Australian police have said they believe the shooting of a police worker by a 15-year-old boy in Sydney on Friday was politically motivated and linked to "terrorism".

The gunman was shot dead by police on Friday afternoon after gunning down a worker at close range as he was leaving the headquarters of the New South Wales Police, police and witnesses said.

Police said they had identified the gunman as a 15-year-old of Iraqi-Kurdish background who had been born in Iran.

"We believe his actions were politically motivated and therefore linked to terrorism," New South Wales Police Commissioner Andrew Scipione told reporters.

Raj Sodhi who lives nearby said he initially thought the “bangs” were from a construction site. “At that time I couldn't comprehend what was happening.”

"It's kind of scary because it has happened at this time of day when people are coming back home from work, in broad daylight. It's kind of unusual, it's kind of scary as well."

Edwin Almeida, an estate agent whose office is opposite the headquarters, said the incident was “surreal”.

Mr Almeida allegedly looked out of his window to see a man with a gun pacing in front of the police headquarters and screaming.

“We looked out the window, saw security guards and what appeared to be a plain clothes police officer with gun drawn pointing at the person that was now lying on the floor surrounded by a pool of blood,” he told AAP.

In a statement, New South Wales police confirmed: “A critical incident investigation has been launched following the death of two people at Parramatta.”