The death toll from a Japanese volcano eruption rose to 47 earlier last week, the worst in 88 years, after more victims were discovered on the ash-covered mountain.

Military searchers resumed a recovery operation with helicopters early on Wednesday a day after officials called off rescue efforts because of poisonous gas and fears of another blast.

The eruption of 3,067-metre Mount Ontake, 200 km west of Tokyo, blanketed the summit with a deadly rain of ash and stone as it was crowded with climbers and hikers enjoying the autumn colours. Police said more victims could still be on the mountain.

The toll exceeds the 43 people killed in a 1991 eruption in southwest Japan and becomes the deadliest volcano since a 1926 eruption on the northern island of Hokkaido, which killed 144 people, according to government data.

Japan is one of the world’s most seismically active countries. There had been no fatalities since the 1991 eruption of Mount Unzen, which caused a pyroclastic flow of superheated current of gas and rock.

Mount Ontake, Japan’s second-highest active volcano, had a minor eruption seven years ago.

Its last major eruption, the first on record, was in 1979.

Hikers said there was no warning of the eruption. Hundreds were trapped for hours before descent became possible.