Prime Minister Anthony Albanese criticized China for a “dangerous” encounter between Chinese and Australian warships while declining to say whether he had raised the issue in recent talks with President Xi Jinping.

One Australian diver was injured when a Chinese destroyer used sonar while near an Australian frigate in international waters last week, official said. Defense Minister Richard Marles said over the weekend that he had raised serious concerns with Beijing about the destroyer’s unsafe and unprofessional behavior.

The U.S., Canadian and Australian militaries have complained multiple times about what they say have been dangerous actions by the Chinese navy and air force in the western Pacific. Analysts say a collision or other accident could spark an international incident and escalate into conflict.

Australia said the Chinese destroyer CNS Ningbo operated its sonar while Australian naval divers were underwater trying to clear fishing nets that tangled the propellers of their ship HMAS Toowoomba.

Albanese said one diver was injured. Defense officials have not specified the injuries or number of divers, but media have reported the divers’ ears were injured.

Analysts say sonar pulses can cause extensive soft tissue damage to divers at close range.

Australia says the Toowoomba notified the Ningbo that diving operations were underway and asked the Chinese to keep clear. But the Ningbo approached using a hull-mounted sonar equipment, placing the divers at risk and forcing them from the water, defense officials say.

China’s Defense Ministry spokesperson Wu Qian on Monday dismissed Australia’s allegations as “completely untrue,” and the ministry denied Australia’s account that the interaction occurred within Japan’s exclusive economic zone.

Wu said the destroyer had been tracking and monitoring the frigate in accordance with international laws and regulations. The Chinese ship had maintained a safe distance and did not interfere with the Australian divers’ operations, he said.

“We urge the Australian side to respect the facts, stop making reckless and irresponsible accusations against China, do more to build up mutual trust between the two sides and create a positive atmosphere for the sound development of relations between the two countries and two militaries,” Wu said.

Between the encounter and Marles’ statement, Albanese spoke to Xi on the sidelines of an Asia-Pacific leaders’ summit in San Francisco. Albanese said on Monday his discussions with Xi were private, rather than a formal bilateral meeting in which content summaries are made public.

“I don’t talk about private meetings on the sidelines, discussions I have with any world leader,” Albanese told Sky News in his Parliament House office.

“It’s something that is a regrettable incident. That’s why we have put our very strong objections to China very clearly, very directly through all of the appropriate channels in all the forums that are available to us,” Albanese added.

He said the incident “does do damage” to Australia’s relationship with China. “This was dangerous, it was unsafe and unprofessional from the Chinese forces,” he said.

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