The Meteorological Agency said Saturday that Mount Sakurajima in Kagoshima Prefecture, 50 km from a just-restarted nuclear plant, is showing signs of increased volcanic activity and that nearby residents should prepare to evacuate.

In line with the move, the Kagoshima municipal government issued an evacuation advisory to the residents of three districts on the island where the volcano is located.

Sakurajima is one of Japan's most active volcanoes and erupts almost constantly. But a larger than usual eruption could be in the offing, an official at the weather agency said.