A US military aircraft with six people on board has crashed off Yakushima Island in south-western Japan, local officials say.
Japan's Coast Guard said one person had been found dead near the crash site of the CV-22 Osprey hybrid plane.
It posted photos of what is believed to be the plane's wreckage off Yakushima.
Japan's NHK broadcaster said the plane's left engine was on fire as it was trying to land at Yakushima Airport on Wednesday.
An eyewitness told local TV that the plane was circling, before exploding and crashing into the sea.
The aircraft was thought to be heading from Iwakuni base in the Yamaguchi region to Kadena base in Okinawa.
Japan's defence ministry said the aircraft disappeared from the radar at 14:40 local time (05:40 GMT) on Wednesday.
The Coast Guard received a distress call seven minutes later, saying the plane had crashed.
It then sent six boats and two helicopters to the scene. At 16:00, the helicopters spotted what looked like a part of the plane and a life raft, a spokesperson told the BBC.
Earlier reports said eight people were on board the aircraft, but that number was later revised down by the coast guard.
Yakushima, in Kagoshima prefecture, is located south of Japan's Kyushu island.
The Osprey is an aircraft that can function as a helicopter and a turboprop aircraft.
More than 50,000 US troops are stationed across Japan.
Some people living on the island of Okinawa, where the aircraft was headed, had previously voiced concerns about the safety of Osprey planes.
The aircraft has been involved in a string of fatal crashes over the years.
In August, a different model Osprey crashed in northern Australia during a military exercise for locally based troops, killing three US marines among the 23 on board.
In 2017, three marines were killed when an Osprey crashed after clipping the back of a transport ship while trying to land at sea off Australia's northern coast.
Source: BBC