This file picture released from Japan's Air Self-Defence Force shows a MU2 rescue aircraft.(AFP photo)

TOKYO, April 14 (Xinhuanet) -- A rescue plane of the Japanese Air Self-Defense Force crashed Thursday afternoon in a mountainous area, north of Tokyo, killing all four crew members aboard.

    The MU-2 plane, which is used for rescue operations, was on a training mission when it went missing about 55 kilometers south ofthe Niigata airport in northwest Japan, according to Kyodo News.

    It was not immediately known what caused the crash, yet the weather and visibility at the time was favorable, the report said.

    The ASDF now possesses five such airplanes. In October 1994, a MU-2 crashed in the Shizuoka Prefecture, south of Tokyo, killing four crew members. Enditem