A volcano in southwestern Japan erupted Thursday for the first time in 250 years, the weather agency said, warning of flying rocks and pyroclastic flows in the area.The eruption of Mt. Io, one of the Mt. Kirishima group of volcanos straddling Miyazaki and Kagoshima prefectures, came after Mt. Shimmoe, another volcano of the group, erupted violently for the first time in about seven years on March 6.Mt. Io erupted around 3:40 p.m. and a plume of ash spewed from the 1,317-meter volcano's crater reaching about 300 meters into the sky, the Japan Meteorological Agency said.[Mt. Io, front, and Mt.READ FULL ARTICLE