Saturday's event was the first fatal one in modern times. At least 63 people suffered injuries and more than 230 climbers had to seek overnight refuge in local lodges. It is still unclear how many may be missing.

Tokyo (AsiaNews/Agencies) - Rescue workers airlifted the bodies of more than 30 climbers who died two days ago following the eruption of Mount Ontake on the Nagano-Gifu prefectural border.

It remains unclear how the victims died, whether from toxic gases, suffocating ash, falling rocks or other causes. Some of the bodies were found buried in ash up to 50 cm deep.

Mount Ontake, a nationally and internationally popular climbing destination, erupted shortly before noon on Saturday, at perhaps the worst possible time, with at least 250 people taking advantage of a beautiful fall Saturday to go for a hike.

The blast spewed large white plumes of gas and ash high into the sky, blotted out the midday sun and blanketed the surrounding area in ash.

At least 36 people are believed to have died, as rescuers found five more people who were presumably killed in Saturday's eruption.

About 550 police, firefighters and members of Japan's Self-Defence Forces personnel joined rescue operations.

The National Police Agency said at least 63 people were injured.

More than 230 climbers who were forced to shelter in local lodges overnight due to poor visibility had descended on their own by Sunday night.

Other climbers remain unaccounted for, some of whom had not notified officials they were climbing the mountain.

The Meteorological Agency's advisory panel on volcanic eruption prediction said the eruption was triggered by a "hydrovolcanic explosion," in which high-pressure water vapour spouts after groundwater is heated by magma. The panel warned that another eruption could occur.

Saturday's eruption was the first fatal one in modern times at Mount Ontake. A similar eruption occurred in 1979, but no one died.

• japan
• mount
• ontake
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• rescue
• recovery
• operations