Miyake Island's Mount Oyama erupted Thursday morning for the fourth time in just over a month, forcing nearby residents to evacuate, the Meteorological Agency said.
Smoke rising as high as 3,000 meters was seen moving eastward from the Izu island, and experts said it was the highest level of activity recently observed from the 813-meter volcano.
The smoke, initially gray but later turning black, was sighted by municipal officials at around 6:30 a.m., the same time the agency confirmed the eruption.