Rescue workers have returned to a Japanese volcano on Monday to recover bodies after an eruption over the weekend killed dozens of people.

Over a thousand soldiers, police and firemen managed to bring down more than 20 bodies by helicopter before the effort was suspended because of toxic gases.

At least 45 climbers are believed to be dead after Mount Ontake erupted without warning while hundreds of hikers including children were admiring the autumn scenery.

Survivors have told stories of seeing people buried alive by ash and battered by a cascade of rocks.

The volcano continued to erupt on Monday and more eruptions are forecast.

Mount Ontake is a popular beauty spot around 200 kilometres west of Tokyo. There was no warning of the eruption which is the first fatal one in modern times at Mount Ontake.

Toshitsugu Fujii from the Japan Meteorological Agency said: “We couldn’t predict the eruption as Mount Ontake has only erupted a few times in the past and we don’t have enough scientific data.”

Japanese authorities watch more than 100 live volcanoes in the country for activity, but say the unpredictability of the steam explosion and Mount Ontake show how enar-impossible it is to out guess mother nature.

There are now concerns about Mount Fuji, just 100 kilometres from Tokyo.