4 confirmed dead on volcano eruption in central Japan

Four climbers among 31 in critical condition were confirmed dead late Sunday due to the Ontake volcano eruption on Saturday in central Japan, local report cited police as reporting.

A total of 31 climbers that trapped on the top area of the volcano were found suffering from hearts or lungs ceasing to function after rescue works resumed early Sunday.

Bodies of the victims, all male, were taken down from the volcano and rescuers are planning to continue their search for the rest 27 on Monday. Rescue works on Sunday suspended in the afternoon due to toxic gas emitted due to the eruption.

The government of the Nagano Prefecture said that a total of 45 people remained unaccounted for as of 11:30 a.m. Sunday, according to Japan's Kyodo News.

The volcano, which straddles Nagano and Gifu prefectures, erupted before noon Saturday, with smoke plumes extending over 10 kilometers high.

Mount Ontake is a popular climbing destination, and at least 250 people were initially trapped on the slopes, though most made their way down by Saturday night.

The report said that more than 40 hikers were forced to shelter in lodges overnight due to poor visibility and 26 climbers who had stayed in a lodge on the Gifu side reached the foot of the mountain before noon, with two of them seriously injured and six suffering minor injuries.

The other climbers who sheltered in lodges on the Nagano side were still on the mountain, said Kyodo.

Panel at the Japan Meteorological Agency said that volcanic activity continues to be high and warned that another eruption could occur, while ranking the latest one as rather small.

They said that the eruption was triggered by a "hydrovolcanic explosion," in which high-pressure water vapor spouts after groundwater is heated by magma, as it could not confirm new magmatic substances in volcanic ash collected at the site, according to Kyodo.

The volcano's last eruption was in 1979 when it expelled over 200,000 tons of ash. It also went through a minor eruption in 1991 and caused multiple volcanic earthquakes in 2007.