U.S. and Japanese officials say a U.S. Air Force helicopter has crashed on Japan's southern island of Okinawa.
Authorities say the crash took place Monday afternoon at a training ground near the U.S. Marine's Camp Hanson.
Video footage showed black smoke rising from a fire in a forested area.
The U.S. Air Force says at least four crew members were on board the aircraft and their status remains unknown.
The HH-60 helicopter was conducting a local training mission at the time of the crash. Authorities say they are investigating the incident.