A prefectural government rescue helicopter with nine people aboard crashed in the mountains in Gunma Prefecture on Friday, killing two of the passengers, the transport ministry and local officials said.

The identities of two were not immediately known. Six other passengers were also discovered in the mountains, but their conditions were unknown. One person remained unaccounted for.

The chopper belonging to Gunma Prefecture lost contact with traffic control earlier in the day, and debris was found in the afternoon in a mountainous area of Gunma.