A US military tiltrotor Osprey, carrying eight people, crashed into the sea off the southern coast of Japan.
The Japanese Coast Guard responded to the scene to conduct search and rescue operations, officials said.
Details of Wednesday’s incident and the fate of the people on board are still unknown, coast guard spokesman Kazuo Ogawa said.
According to him, the coast guard received an emergency call from a fishing boat that was near the accident site off the island of Yakushima, located south of the main Japanese island of Kyushu.
The tiltrotor Osprey is a hybrid aircraft that takes off and lands like a helicopter, but during flight it can spin its rotors forward and fly much faster like an airplane. These tiltrotors are in service with the US Marine Corps, Navy and Air Force.