Mt. Asama in eastern Japan erupted Sunday, prompting the weather agency to warn of possible flying rocks and pyroclastic flows within about a 2-kilometer radius of the crater.
The eruption, which followed one earlier this month, occurred at 7:28 p.m., with smoke reaching about 600 meters above the mountain, according to the Japan Meteorological Agency, which maintained the volcanic alert level at 2 on a scale of 5. Level 2 means people should not approach the crater.
The agency said it will closely monitor the volcanic activity, citing the possibility of an eruption on a similar scale.
The 2,568-meter-high volcano, which straddles Gunma and Nagano prefectures and is located near the Karuizawa resort area northwest of Tokyo, experienced a small eruption on Aug. 7, causing the alert level to be raised from 1 to 3.
The agency lowered the alert level to 2 last Monday.