Defence has accused a Chinese navy vessel of shining a laser at an Australian aircraft.
Defence confirmed in a statement released on Saturday that on 17 February the P-8A Poseidon detected a laser illuminating the aircraft while in flight over Australia’s northern approaches.
The laser was detected as emanating from a People’s Liberation Army – Navy (PLA-N) vessel which, in company with another PLA-N ship, was sailing east through the Arafura Sea at the time of the incident. Both ships have since transited through the Torres Strait and are in the Coral Sea.
Defence called the event a "serious safety incident" with "the potential to endanger lives".
"We strongly condemn unprofessional and unsafe military conduct," Defence continued. "These actions could have endangered the safety and lives of the ADF personnel.
"Such actions are not in keeping with the standards we expect of professional militaries."
Prime Minister Scott Morrison declared the incident "an act of intimidation" by China, "one that was unprovoked, unwarranted".
"I thought it was a reckless and irresponsible act," he told reporters in Melbourne on Sunday.
Morrison said Australia would be "making our views very clear" to the Chinese government through defence and diplomatic channels.