A man found in waters near the crash site of a US Osprey military aircraft off southwestern Japan and later confirmed dead has been identified as one of the eight crew members. Search and rescue efforts for the remaining crew members are continuing.

The crash occurred just before 3 p.m. local time on Wednesday near the island of Yakushima in Kagoshima Prefecture.

Local coast guard officials said that the aircraft requested an emergency landing at Yakushima Airport at around 2:35 p.m.

The Defense Ministry said the Osprey dropped off Japan Self-Defense Forces radar screens near the island five minutes later.

The coast guard said many pieces of what appeared to be wreckage of the aircraft were spotted in nearby waters.

It said the waters around the crash site are about 30 meters deep and that a sonar device is being used in the search.

Six coast guard patrol vessels and two planes, as well as Self-Defense Forces aircraft and ships, have been dispatched to the site. Police helicopters are also joining the search.

The US military told NHK that the Osprey was involved in an aircraft mishap while performing a routine training mission.

It added that emergency personnel are on scene conducting search and rescue operations, and the cause of the mishap is currently unknown.

Japan's Defense Ministry says this is the first fatal accident involving an Osprey in the country.