Miyake Island's Mount Oyama erupted Friday evening and sent smoke some 8,000 meters into the air, the highest altitude of any of the volcano's recent eruptions, the Meteorological Agency said.
The volcano had rumbled back to life in late June, and the first confirmed eruption came July 8.
The latest eruption of the 813-meter volcano occurred at around 5:05 p.m., with the agency calling on local residents to be on full alert.