Japanese authorities on Wednesday issued an advisory against further travel by civilian and military aircraft as the volcano at the heart of the sprawling Tokaido region belched ash and lava at the surrounding area.
Mount Aso, located about 140 miles northeast of Tokyo, had increased its level of activity Monday, according to Kyodo News, a Japanese news agency.
The Ashfall to Avoid advisory was issued for Aso, near the popular Mount Fuji tourist site, and its western flank.
Aso “might erupt very soon,” according to the advisory, issued by local authorities.
“Volcanic activity has been increased and other circumstances have been worsened. At this moment, we recommend not to operate civilian or military flights into Mount Aso,” the advisory said.
The Mountain Safety Council, a government agency, said: “There have been violent and strong shaking and some falling ash. We strongly advise people to stay away from the mountain as a high proportion of the 1,100-foot-high Aso mountain remains unstable, exposing concrete and earth for approximately 75 miles to the south.”
Heavy rainfall and strong winds had caused landslides and possible fires, the agency said.
Satellite images showed smoke billowing from Aso, which is Japan’s largest active volcano.
Mount Aso last erupted in 2016, sending plumes of ash and foam billowing skyward.
Associated Press writer Mari Yamaguchi contributed to this report.