This makes for pretty terrifying viewing...
Mount Ontake volcano in Japan erupted and was caught on camera by a group of mountain climbers.
A cloud of volcanic ash slowly makes its way towards the group before engulfing them.
According to officials, a total of seven people were left unconscious, eight seriously injured and more than 250 were left stranded on the mountain.
Watch the clip in full below:
http://www.youtube.com/watch?v=7Ea3uED1Zgc
Video via YouTube/kuroda terutoshi