TOKYO -- At least two people were confirmed dead after a Japanese search and rescue helicopter with nine people aboard crashed Friday in central mountains hours after it lost contact.

Rescue aircraft dispatched by the Defence Ministry found eight of the crewmembers at the site. Two of them were later confirmed dead, while the conditions of the other six were still unknown, according to Ryu Kumakawa, an emergency response official at the Gunma prefecture. The ninth man is missing.

Officials at the prefecture north of Tokyo said the Bell 412EP helicopter carrying seven local rescue workers and two crew from a flight service company lost contact an hour after takeoff. The planned two-hour flight was to monitor a mountain trail opening for climbers this weekend.

Television footage showed debris of the helicopter scattered on the mountainside, apparently after it crashed while tearing down trees.

The cause of the crash is under investigation. Prefectural officials said the helicopter did not report any abnormality until it lost contact.

Japanese media quoted witnesses as saying the helicopter was flying extremely low minutes before the crash.