Mount Ontake
© Reuters/Kyodo
Smoke rises from Mount Ontake, which straddles Nagano and Gifu prefectures September 27, 2014.
A volcano in central Japan has erupted, sending ash clouds down the mountains' slope for more than 3 kilometers. At least eight people have been injured and aircraft have been forced to divert to avoid the dangerous area.The Ontake volcano on the border of Nagano and Gifu prefectures, 200 kilometers west of Tokyo, started erupting at about 11:53 local time (02:53 GMT), NHK reported, citing Japan's Meteorological Agency.

NHK released a video showing the volcano spewing thick, gray smoke into the air."Seven people were slightly injured and one person suffered serious injuries as a result of the eruption," Makoto Hasegawa of the Nagano prefecture fire department told Reuters."Airplanes are diverting their flying routes to avoid the ash cloud," he added.

Japan's Meteorological Agency declared a level 3 volcano alert on a 1 to 5 scale, which means people are advised to stay away from the mountain. The agency warned that the debris from the volcano could fall as far as 4 kilometers away.

Volcanic alerts in Japan

Channel News Asia cited an official of the Nagano prefecture fire department as saying that the casualty numbers may rise as new reports arrive.
Ontake eruption
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Stratovolcano Ontake (Ontake-san) is the second highest volcano in Japan at 3,067 meters. It is also a popular destination for religious pilgrimages.

It was inactive until 1979, but then it underwent a series of eruptions. The latest was in 2007.