A volcano erupted near Tokyo early on Monday, spewing a plume of smoke more than a mile (1.6 kilometers) high and raining ash down on parts of the city. There were no immediate reports of injuries or damage.
Mount Asama, about 90 miles (145 kilometers) northwest of Tokyo, erupted at 1:51 am (0451 GMT) Monday, according to Japan's Meteorological Agency. Chunks of rock from the explosion were found about 3,300 feet (1,000 meters) away from the volcano. The agency said volcanic ash fell on nearby areas as well as parts of Tokyo. TV reports showed neighborhoods sprinkled with white flakes.
An alert level of three, which urges nearby residents to take caution, was kept in place for a 2.5 mile (4 kilometer) radius. Alert level four advises residents to prepare for evacuation, while level five, the highest, orders evacuation, according to the agency. The last major eruption of Mount Asamo took place in September 2004, the agency said.
With 108 active volcanos, Japan is among the most seismically busy countries in the world. The country lies in the "Ring of Fire" _ a series of volcanoes and fault lines that outline the Pacific Ocean.