Mount Asama in north-central Japan erupted early Monday, spewing volcanic ashes to an altitude of 2,000 meters, the Japan Meteorological Agency said. The agency issued a warning of continued large ash deposits in the surrounding 4-kilometre radius. No casualties have been reported. The mountain erupted at about 1:51 am from the crater, and volcanic smoke was detected until around 8 am, DPA reported. Mount Asama, on the border between Gunma and Nagano provinces, erupted in August.