The manager of one of the mountain lodges on Mount Ontake has been describing how he helped lead about 50 trekkers to safety.
Yusuke Kodera, 34, runs a hut adjacent to Lake Ninoike. At an altitude of 2,900 meters, it is one of the closest buildings to the summit.
When the ground up opened just before midday Saturday, filling the air with ash and rock, panicked trekkers ran inside.