Tokyo: The Japan Meteorological Agency on Saturday raised the warning level to an unprecedented 4 for Mount Sakurajima in Kagoshima prefecture due to increased volcanic activities.
Mount Sakurajima is one of Japan's most active volcanoes and erupts frequenctly, the agency said.
But a larger than usual eruption could be in the offing, an official from the agency said, adding "there is danger that stones could rain down on areas near the mountain's base, so we are warning residents of those areas to be ready to evacuate if needed," Xinhua news agency reported.
Mount Sakurajima is located only about 50 km far from the Sendai Nuclear Power Plant, whose No. 1 reactor had restarted on Tuesday.
Agency officials have pointed out that the plant is too close to some giant calderas, with the closest one only 40 km away and it might result in serious destruction and damage if an eruption occur.