TOKYO (AP) — The Japanese coast guard says a U.S. Air Force Osprey based in Japan crashed during a training mission off of the country’s southern coast, killing at least one of the eight crew members.

Japanese coast guard spokesperson Kazuo Ogawa says the cause of Wednesday’s crash and the status of the seven others on board were not immediately known.

U.S. Air Force Special Operations Command says that the CV-22B Osprey was from Yokota Air Base and assigned to the 353rd Special Operations Wing.

Ospreys take off and land like helicopters but can rotate their propellers to fly like planes .

They have had a number of accidents in the past.