(Newser) – At least 16 people skiing on the slopes of a volcano in central Japan were injured by flying rocks during a surprise eruption and a subsequent avalanche Tuesday, and one person later died. Six skiers, including the man who died, were among 30 Japanese soldiers who were participating in ski training when they were buried by the avalanche about a half hour after the volcanic eruption, fire department and defense officials say. One or two of the injured were on a gondola when the window was shattered by volcanic rocks, and the others were believed to have been hit by rocks while on the slopes, the AP reports.

Officials say they believe everybody has been accounted for. Only the crater had been off-limits because of low-level volcanic activity before Mount Kusatsu-Shirane erupted with rocks and ash around 10am. The Japan Meteorological Agency has since banned access to the mountain, and a large swath of the snow-covered volcano was covered by dark gray ash later in the day. Five of the civilian skiers suffered serious injuries such as broken bones, but none of the injuries were life-threatening, says a regional fire department official. (Authorities in the Philippines warn that a violent eruption is "imminent.")

