TOKYO - At least 31 people were presumed dead yesterday, near the peak of a Japanese volcano that had erupted unexpectedly a day earlier while it was packed with hikers out to admire the autumn foliage.
Police said the 31 people were found in "cardiopulmonary" arrest, but declined to confirm their deaths pending a formal examination, as per Japanese custom.
An official in the area said rescue efforts had been called off due to rising levels of toxic gas near the peak, as well as approaching nightfall.
Hundreds of people, including children, were stranded on Mount Ontake, a popular hiking site, after it erupted without warning on Saturday, sending ash and rocks pouring down the slope for more than 3km.
Most made their way down later on Saturday, but about 40 spent the night near the 3,067m peak. Some wrapped themselves in blankets and huddled in the basement of buildings.
More than 40 people were injured, several with broken bones.
The volcano was still erupting yesterday, pouring smoke and ash hundreds of metres into the sky. Ash was found on cars as far as 80km away.
Volcanoes erupt periodically in Japan, one of the world's most seismically active nations, but there have been no fatalities since 1991, when 43 people died in a pyroclastic flow, a superheated current of gas and rock, at Mount Unzen in south-western Japan.
Ontake, Japan's second-highest volcano 200km west of Tokyo, last erupted seven years ago. Its last major eruption was in 1979.
An official at the volcano division of the Japan Meteorological Agency said that, while there had been a rising number of small earthquakes detected at Ontake since Sept 10, the eruption could not have been predicted easily.
"There were no other signs of an imminent eruption, such as earth movements or changes on the mountain's surface," the official told Reuters.
"With only the earthquakes, we couldn't really say this would lead to an eruption."