A Chinese fighter jet has dropped flares in front of an Australian surveillance plane over the South China Sea, in an incident the Albanese government has called “unsafe and unprofessional”.

Defence Minister Richard Marles said the RAAF P-8A Poseidon aircraft was on a routine patrol on Sunday when the People’s Liberation Army jet flew alongside it.

He said the Chinese aircraft twice released flares “very close” to the Australian plane.

“Having reviewed the incident very carefully, we’ve deemed this to be both unsafe and unprofessional,” he said in Canberra on Monday.

“It’s because of determining it to be both unsafe and unprofessional that we are now making this public.”

No Australian personnel were hurt in the interaction, but Marles said the outcome could have been different.

The federal government has complained about the incident to the Chinese embassy in Canberra and made representations via the Australian embassy in Beijing.

Pressed on how close the flares were released from the Australian plane, Marles declined to specify an exact distance, but said it was “very close”.

“We’re talking about a P8 aircraft … it is a large jet aircraft which is not particularly manoeuvrable in an instant and the proximity of these flares meant that it was unsafe,” he said.