One police officer has been run over by a reversing car while another has been shot in the arm in an incident in Sydney's inner west.
Four officers were on Friday evening approaching a Honda sedan parked at an Earlwood reserve when the vehicle began to reverse, striking an officer.
Police say one of the four officers - a 44-year-old senior constable - then shot his gun, with a fragment of the bullet striking another officer in the forearm.
A 27-year-old male constable will undergo surgery later on Saturday to remove the fragment. He is in a stable condition.
The driver of the vehicle, a 26-year-old man, and his 25-year-old female passenger are yet to be charged and have been released from custody.
Detective Superintendent Paul Devaney said the officers' actions would be subject to an internal review.
The four officers - two of whom were in plain clothes - were driving an unmarked police vehicle.
"They were engaged in a proactive operation for street-level crime and violent crime, that's a known hotspot for crime and it was a car parked in an isolated position in the car park ... it raised their suspicion," Det Supt Devaney told reporters.
"In situations like this, it's what we perceive as a last resort, the use of our firearm ... no officer goes to work hoping to discharge their firearm.
"I don't know what was playing on the mind of the officer at the time ... that is the subject of the investigation."