TOKYO -- Japan raised alert levels on a small southern volcanic island on Wednesday, urging its 105 residents to prepare for an evacuation amid growing risks of an eruption.
Japan Meteorological Agency raised the warning for Kuchinoerabu island from two to four on a scale of five. The agency said it has detected an increased activity at the island's Shindake volcano.
The volcano had the last major eruption in May 2015, forcing the island's entire population of about 140 at that time to seek safety on nearby Yakushima island for several months. A total of 105 residents were back on the volcanic island as of Aug. 1, town officials said.
Local authorities told all residents to start preparing for an evacuation in case of another violent eruption, and urged elderly people within the 3-kilometre (2-mile) high-risk zone to leave immediately to a community centre at a safer location on the island.
The agency cautioned against a possibility of getting hit by volcanic rocks and pyroclastic flows during an eruption.
Kuchinoerabu is located south of Japan's southern main island of Kyushu. It can be reached only by a daily ferry from Yakushima, a bigger island about 12 kilometres (7 miles) to the east.
Japan has about 100 active volcanoes and is frequently jolted by earthquakes.