Three Marines were killed when an aircraft crashed on an island off Australia’s northern coast, the Marine Corps said in a statement Sunday.
The MV-22B Osprey, tiltrotor aircraft came down “while transporting troops during a routine training exercise,” on Melville Island, north of Darwin, the statement said.
Five others in “serious condition” were transported to the Royal Darwin Hospital about 60 miles to the south of the island, the statement said. “There were a total of 23 personnel on board,” it added.
A spokesperson confirmed to NBC News that all of those on board were Marines.
“The Marines aboard the aircraft were flying in support of Exercise Predators Run,” the statement said, adding that “the cause of the incident is under investigation.”
Hundreds of troops from the U.S., Australia, the Philippines, East Timor and Indonesia are taking part in the exercise which focuses on Melville which is part of the Tiwi Islands.
Around 150 U.S. Marines are currently based in Darwin and up to 2,500 rotate through the city every year.
Calling it a “tragic incident,” Australia’s Prime Minister Anthony Albanese told a news conference that his government’s focus was “very much on incident response and on making sure that every support and assistance is given.”
He added his government and defense department were “also very much focused on providing that practical assistance on the ground.”
At a joint news conference, with Northern Territory Chief Minister Natasha Fyles, the region’s Police Commissioner Michael Murphy said helicopters and fixed-wing aircraft were deployed to return the rest of the injured from the remote location.
The Osprey that crashed was one of two that had flown from Darwin to Melville on Sunday, Murphy said.
“We acknowledge that this is a terrible incident,” Fyles added. “The Northern Territory government stands by to offer whatever assistance is required.”
Military cooperation between the U.S. and Australia has ramped up in recent years. Four Australian soldiers were killed during exercises last month when their helicopter crashed into the ocean off the coast of Queensland.