Mount Asama, a volcano in central Japan, erupted Sunday, prompting the Meteorological Agency to warn of possible airborne rock debris and pyroclastic flows within about a 2-kilometer radius of the crater.
The eruption, which followed one on Aug. 7, occurred at 7:28 p.m., with smoke reaching about 600 meters above the mountain, according to the agency.
It kept the volcanic alert level unchanged at 2 on a scale of 5, warning residents not to approach the crater.
The agency said it will closely monitor volcanic activity, citing the possibility of an eruption on a similar scale.
Following the Aug. 7 eruption, the agency raised the alert level from 1 to 3, and lowered it to 2 on Aug. 19.
The 2,568-meter-high volcano sits on the border of Nagano and Gunma prefectures.