China accuses Australia of air intrusion in S China Sea

Australia's statements about an incident involving Chinese military aircraft over the South China Sea are an attempt to cover up an Australian "intrusion" into Chinese airspace, the Chinese defence ministry says.

The defence ministry says it has complained to Canberra about the matter.

The ministry was referring to an incident around the Paracel Islands in which Australia claimed a Chinese fighter jet dropped flares near one of its maritime patrol planes.

Australia called the incident "unsafe and unprofessional".

"We urge Australia to immediately stop infringement, provocation and hype, strictly restrain the actions of front-line naval and air forces," China's ministry spokesperson said in a statement.

The incident was made public by Australian Defence Minister Richard Marles on Monday amid fears Beijing is growing more aggressive in the contested region.

While the exact location of the planes at the time of the incident has not been released, Mr Marles reiterated on Tuesday that the planes were in international airspace at the time.

"At every moment our crew was adhering to international law," he told reporters.

China's claim to the Paracel Islands, where the incident is believed to have occurred, was not legitimate and Australia had operated militarily in the region for decades, security analyst and academic Jennifer Parker said.

with AAP