Kagoshima, Japan - A US military Osprey aircraft crashed on Wednesday off a Japanese island, killing one crew member and leaving five unaccounted for, the coastguard said, in the latest incident involving the tilt-rotor military aircraft.

One unconscious person had been found in the sea near the scene of the crash off the island of Yakushima but was later "confirmed dead in hospital", the coastguard said in a statement.

An emergency management official in the Kagoshima region where the crash took place said police had received information that the aircraft had been "spewing fire from a left engine".

The US military in Japan, where it has around 54,000 personnel, was not immediately available for comment.

Accidents Driver dies after crashing car into White House at high speed

The coastguard said it has mobilized patrol ships and aircraft around Yakushima, which lies south of Japan's southernmost main island of Kyushu.

Japanese broadcaster NHK reported that the Osprey was on its way from the Iwakuni US base near Hiroshima in the Yamaguchi region headed for the Kadena base further south in Okinawa.

NHK also cited defense ministry sources as saying that the aircraft was a CV-22 Osprey belonging to the US Yokota air base in Tokyo.

The Osprey, developed by Bell Helicopters and Boeing and which can operate like a helicopter or a fixed-wing plane, has suffered a string of fatal crashes over the years.

In August, a crash in northern Australia killed three US marines among the 23 on board. It was the fourth incident involving an Osprey since 2016.

This month, five US service members were killed when a helicopter of unspecified type crashed into the Mediterranean during a training exercise.