TOKYO, Oct. 8 (Xinhua) -- Mount Aso, a volcano on Japan's main southern island of Kyushu, had an explosive eruption early Saturday, Japan Meteorological Agency said.
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 the agency.
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 rocks. No injury has been reported yet.
The agency said that it is unclear whether the eruption was related to powerful earthquakes that hit southwestern Japan in April.
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 on May 1.