A volcano has erupted in central Japan, catching mountaineers by surprise and trapping hundreds of people.

At least 11 people were injured, including seven who were rendered unconscious. Mount Ontake, on the main Japanese island of Honshu, erupted yesterday shortly before noon local time, spewing large white plumes of ash high into the sky and sending people on the mountainside fleeing, covering some in ash.

More than 250 people were trapped on the mountain and a nearby peak in areas that were dangerous to approach.