Sat Aug 5, 2017 12:29PM
The US military's Bell Boeing V-22 Osprey aircraft crashed off the east coast of Australia on Saturday. |(File photo)
The US military's Bell Boeing V-22 Osprey aircraft crashed off the east coast of Australia on Saturday. |(File photo)

Several US service members are feared dead after their aircraft crashed off the east coast of Australia, the United States Marine Corps has said.

It is not clear yet how many service members were on board the MV-22 Osprey tilt-rotor at the time of the “mishap” on Saturday, the military said.

US Marines based in Japan said there was "an active search and rescue operation ongoing for service members involved in an MV-22 mishap off the east coast of Australia".

According to reports, small boats and aircraft from the 31st Marine Expeditionary Unit and the Bonhomme Richard Expeditionary Strike Group were involved in the rescue operation.

The Osprey heli-plane is essentially the assault support aircraft for the Marines, with two engines positioned on fixed wing tips that allow it to land and take off vertically.