China has been accused of placing the lives of Australian personnel in danger while allegedly shining a laser at an RAAF aircraft off the Northern Territory.

The Australian Defence Force (ADF) said the incident happened on Thursday at 12.35am.

The P-8A Poseidon aircraft with 10 personnel on board was flying over Australia’s northern approaches.

A military-grade laser was detected coming from a People’s Liberation Army Navy vessel.

“Illumination of the aircraft by the Chinese vessel is a serious safety incident,” an ADF statement on Saturday said.

“We strongly condemn unprofessional and unsafe military conduct.

“These actions could have endangered the safety and lives of the ADF personnel.”

The vessel was in the company of another Chinese ship and sailing east through the Arafura Sea at the time of the incident.

Both ships have since passed through the Torres Strait and are in the Coral Sea.

ADF observed the Chinese vessels in the region’s waters six times over five days, including in the Timor and Arafura seas.

-with AAP