An Australian army helicopter crashed in waters off the country’s northeast coast, interrupting high-profile military exercises with troops from more than a dozen countries including the US.

A search-and-rescue operation is underway for the four crew members who were on the MRH90, Deputy Prime Minister Richard Marles said Saturday. The helicopter ditched shortly after 10:30 p.m. local time close to Hamilton Island, near the coast of Queensland state.

The helicopter was taking part in Exercise Talisman Sabre, biennial defense maneuvers featuring more than 30,000 troops, including a large US contingent. The two-week program, partly a showcase of Australian-US unity to discourage potential Chinese aggression, was suspended for all forces because of the crash.

“These are early days and there will be much more information to be provided,” said Marles, who is also the defense minister. “We desperately hope for better news.”

This year’s Talisman Sabre was the largest yet, featuring livefire drills and amphibious landings. The exercise coincided with a visit to Australia from US Secretary of State Antony Blinken and Secretary of Defense Lloyd Austin for talks with Marles and Australian Foreign Affairs Minister Penny Wong.