TOKYO, Oct. 8 (Xinhua) -- Mount Aso, a volcano on Japan's main southern island of Kyushu, had an explosive eruption early Saturday, with volcanic ash spreading hundreds of kilometers away to western Japan.
The eruption was observed at around 1: 46 a.m. local time at one of the peaks of the mount, spewing volcanic ash 11,000 meters into the sky, said Japan Meteorological Agency.
It was the first explosive eruption at the peak since January 1980.
The agency raised the alert level for the volcano to level 3 on a scale of 5, restricting entry into the mount and warning of falling rocks.
Local residents in surrounding areas have been warned of heavy volcanic ash fall as well as volcanic gas and falling rocks within 2 km range of the volcano. No injury has been reported yet.
Volcanic ash was observed in not only Kumamoto and Oita prefectures, but also in Kagawa, Ehime and Kochi prefectures in western Japan.
A power outage possibly caused by volcanic ash has been affecting over 5,000 households in the city of Aso and three other municipalities since 6:00 p.m..
Kyushu Railway Co. has suspended services for a section of a line that runs through the outskirts of the volcano.
The weather agency said that the mount is in an unstable condition and eruption on the same scale could occur again.
It is unclear whether the eruption was related to powerful earthquakes that hit southwestern Japan in April, said the agency.
Mount Aso is the largest active volcano in Japan. The mount also had a small eruption at 9:52 p.m. Friday, following one that occurred five months ago in May.
