A U.S. Navy transport plane carrying 11 people crashed in waters southeast of Japan's Okinawa Island on Wednesday as it flew to the aircraft carrier the USS Ronald Reagan، the U.S. Seventh Fleet said، according to Reuters.
The crash happened at 2.45pm Japan time (5.45am GMT).
"USS Ronald Reagan is conducting search and rescue operations. The cause of the crash is not yet known،" it said in a press release.
Japanese Minister of Defence Itsunori Onodera told reporters the U.S. Navy had informed him that the crash in the Philippine Sea may have been a result of engine trouble.
The propeller powered transport plane، a C-2 Greyhound، carries personnel، mail and other cargo from mainland bases to carriers operating at sea.
The aircraft has been in operation for more than five decades and is due to be replaced by the long-range tilt-rotor Osprey aircraft.
Noteworthy، in August، the US Navy lost 10 personnel when the USS John McCain collided with a tanker off Singapore.
Two months earlier، the USS Fitzgerald and a cargo ship crashed into each other off Japan، leaving seven sailors dead.