Rescue operations were completed by nightfall.
A volcanic eruption in central Japan killed one and inured at least 12 people.
The eruption on Mount Kusatsu-Shirane sent rocks and volcanic ash spewing across the mountains near a popular ski resort approximately 93 miles northwest of Tokyo.
“There was a huge boom then a big plume of black smoke in the sky,” one skier told NHK, the public broadcaster. “I had no idea what was going on.”
Eight of the people injured were soldiers conducting drills for rescue operations nearby, Associated Press reported. A soldier was the one fatality.
Around 80 skiers took refuge in a gondola station at the top of the mountain during the eruption. By nightfall, rescue teams on snowmobiles and military helicopters had rescued everyone from the top of the mountain, according to the same AP report.
Early reports linked the eruption with an avalanche, but those reports have not been confirmed.
The area is know for its hot spring resort, Kusatsu Onsen, home to 13 public baths said to have healing powers.