AT LEAST ONE crew member has died after a US military Osprey aircraft carrying six people crashed off southern Japan, coast guard officials said.

The cause of the crash and the status of the five others on the aircraft were not immediately known, coast guard spokesperson Kazuo Ogawa said.

Initial reports said the aircraft was carrying eight people, but the US military later revised the number to six.

The coast guard received an emergency call from a fishing boat near the crash site off Yakushima, an island south of Kagoshima on the southern main island of Kyushu, Ogawa said.

Debris believed to be from the US military osprey aircraft discovered yesterday. Alamy Alamy

Coast guard aircraft and patrol boats found one person, who was later pronounced dead at a nearby hospital, and grey-coloured debris believed to be from the aircraft, Ogawa said.

They were found about less than a mile off the eastern coast of Yakushima. An empty inflatable life raft was also found in the area.

“The government will confirm information about the damage and place the highest priority on saving lives,” Chief Cabinet Secretary Hirokazu Matsuno told reporters.

The Osprey is a hybrid aircraft that takes off and lands like a helicopter, but during flight can rotate its propellers forward and cruise much faster like an airplane.

Versions of the aircraft are flown by the US Marine Corps, Navy and Air Force.

Ogawa said the aircraft had departed from the US Marine Corps Air Station Iwakuni in Yamaguchi prefecture and crashed on its way to Kadena Air Base on Okinawa.

Japanese vice defence minister Hiroyuki Miyazawa said the Osprey had attempted an emergency sea landing.

Kyodo News agency, quoting Kagoshima prefectural officials, said witnesses reported seeing fire coming from the Osprey’s left engine.

It said a Japanese military base in Saga in southern Japan decided to postpone planned Osprey flight exercises today.

US and Japanese officials said the aircraft belonged to Yokota Air Base in western Tokyo.

Japan’s chief cabinet secretary Hirokazu Matsuno said the search will continue. Alamy Alamy

Air Force officials at Yokota said they were still confirming information and had no immediate comment.

Ospreys have had a number of accidents in the past, including in Japan, where they are deployed at both US and Japanese military bases.

In Okinawa, where about half of the 50,000 American troops in Japan are based, governor Denny Tamaki told reporters Wednesday that he will ask the US military to suspend all Osprey flights in Japan.

In December 2016, a US Marine Corps Osprey crashed off the Okinawa coast, injuring two of the five crew members and triggering complaints among local residents about the American bases and the Osprey’s safety record.

A US Marine Corps Osprey with 23 Marines aboard crashed on a north Australian island in August, killing at least three and critically injuring at least five during a multinational training exercise.

It was the fifth fatal crash of a Marine Osprey since 2012, bringing the death toll at that time to at least 19.