The crash of the Osprey sparked a large search effort by US and Japanese teams [Source: Reuters]

American and Japanese search teams have found five bodies in the wreckage of a US military aircraft that crashed near Yakushima island last week.

The aircraft, a CV-22 Osprey hybrid plane, was carrying eight people when it crashed last week. Only one had previously been found.

Two of the five bodies found on Monday have so far been recovered.

The crash prompted Tokyo to ask the US to ground its Osprey planes in Japan.

At the time of the crash, the Osprey had been on a training flight from a US Marine Corps air base in Yamaguchi Prefecture and was headed towards Kadena Air Base in Okinawa.

It requested an emergency landing on Yukushima island before crashing offshore.

Eyewitnesses later reported that the aircraft flipped over and was on fire before crashing. The cause of the incident remains unclear.

In a statement on Monday, US Air Force Special Operations Command said that the combined US and Japanese teams working to find the aircraft “had a breakthrough when their surface ships and dive teams were able to locate remains, along with the main fuselage of the aircraft wreckage”.

Attempts to recover the remaining crew members from the wreckage continue, the statement added. They have not yet been identified.

The body of the first victim identified was recovered just hours after the crash.

The Air Force named him as Staff Sgt Jake Galliher, a 24-year-old Massachusetts native who was part of an intelligence unit assigned to Yokota Air Base in Japan.

First introduced in 2007, Ospreys function both as a helicopter and an aircraft with a propeller.

In a separate incident in August, a different model Osprey crashed during a military exercise in Australia, killing three US Marines and injuring 20 others.

Another crash involving an Osprey in the California desert last year caused the deaths of five Marines.

Japan – the only other nation to operate Ospreys – temporarily grounded its own fleet of the aircraft last week.

It also asked the US to ground the 30 Ospreys it had based in Japan until inspections could be carried out to confirm their safety.

In response to a query from the BBC, the Pentagon said that the unit to which the aircraft belonged is “not conducting flight operations” and that the US “is taking all appropriate safety measures, as we do for every flight and every operation”.

As part of a Japan-US military agreement, Japan will largely be excluded from the investigation into the crash.

This rule and the US refusal to ground its fleet prompted anger in Japan.

Pentagon deputy press secretary Sabrina Singh said the US has “already started sharing information about the accident with our Japanese partners”. “We have good communications between our senior leaders and are in constant dialogue regarding aviation safety and other safety-related issues.”