36 now feared dead in Japanese volcano disaster

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Rescue teams searching Japan's Mount Ontake for missing climbers suspended operations as the volcano continued to shoot gas, rocks and ash into the air.

At least 36 people are believed to have died when Mt Ontake erupted unexpectedly on Saturday.

Many of those still stranded have been taking refuge in mountain lodges - some are injured and unable to descend on their own, while others are unwilling to take the risk.

However, a group of hikers first reported missing near the summit are now presumed dead. The group were located by police in a state of 'cardiac arrest' - but police declined to confirm their deaths pending a formal examination, as per Japanese custom.

Only four people have so far been confirmed dead in Japan's first fatal volcanic eruption since 1991, and at least 60 have been injured, some with broken bones. 

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Soldiers, firefighters and police pictured conducting rescue operations on the slopes of the ash-covered volcano 

Desperate rescue: Mount Ontake erupted shortly before noon on Saturday, spewing large white plumes of gas and ash into the sky and blanketing the surroundings

Rescue efforts are now focusing on finding and evacuating survivors from the area. Today seven people were airlifted out by helicopter

A survivor is carried off the volcano by a group of soldiers. Some survivors are unable to descend on their own while others are not willing to take the risk

Rescue workers search for missing climbers and hikers on the volcano after the eruption left dozens injured, missing or stranded

Firefighters and members of Japan's Ground Self Defence Forces conduct rescue operations on Mount Ontake. A blanket of ash covered nearby buildings and land

Two tanks from the Ground Self Defence Force enter Otaki village in a bid to help support the rescue operations

Hundreds of soldiers, police officers and firefighters have moved into the area to help rescue those still stranded on the volcano

News crews and a tank parked side-by-side in the area near Mount Ontake a day after the volcano erupted without warning

Smoke continues to emanate from Mount Ontake a day after the eruption which stranded more than about 40 hikers and injured another 42

Military helicopters today plucked seven people off the mountainside and workers were helping others make their way down the slopes. One woman was being carried on a stretcher, and a man with a broken arm was walking down. All were conscious and most could walk, though details of their conditions were unclear.

Japanese television footage also showed a soldier descending from a helicopter to an ash-covered slope, helping latch on a man and then the two of them being pulled up. 

The Self-Defense Force, as Japan's military is called, has deployed seven helicopters and 250 troops. Police and fire departments are also taking part in the rescue effort. 

An official in the area said rescue efforts for had now been called off due to rising levels of toxic gas near the peak, as well as approaching nightfall. 

Most of those caught in the eruption made their way down at the time, but about 40 spent the first night near the peak. Some wrapped themselves in blankets and huddled in the basement of buildings.

'The roof on the mountain lodge was destroyed by falling rock, so we had to take refuge below the building,' one told NHK national television. 'That's how bad it was.'

More than 60 people were injured, several with broken bones. Earlier, the Fire and Disaster Management Agency had said authorities were trying to confirm the whereabouts of 45 people but it was not clear whether that figure included the 36 hikers presumed dead.

The volcano was still erupting today, 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 southwestern Japan.

Rescuers had planned to bring four of them down the mountain by later tonight, Jiji Press said citing police sources.

Although a handful of people were rescued today, operations have been put on hold after a rise in levels of toxic gases on the volcano

The eruption covered a vast area in volcanic ash. Pictured are rescue workers trekking up the volcano in an attempt to locate trapped hikers

The rescue teams pictured descending an area not hit by ash, after they called off the search operation due to a rise in toxic fumes

Smoke emanating from the volcano - as seen at dusk from the nearby Otaki Village, in Nagano, Japan

Pictured left, a plume of smoke billows into the sky above a set of cabins built on the volcano, while right, a group of rescuers traverse the slope

Some 550 soldiers, police officers and firefighters were involved in a large-scale search-and-rescue operation in a bid to save dozens of hikers who were thought to have been stranded on the volcano since it erupted without warning spewing ash, rocks and steam into a sunny autumn weekend busy with tourists and hikers.

A suffocating blanket of ash up to 20 centimetres deep covered a large area of the volcano, had forced up to 150 to seek refuge in mountaintop shelters at one point.

The mountain is popular among hikers particularly in late September as leaves turn their colours.

Walkers at the top of the Japanese volcano were forced to run for their lives after it started to erupt without warning, sending a cloud of ash and rock streaming down the mountainside.

Within seconds, the cloud covered an area more than two miles wide from the summit of Mount Ontake with witnesses claiming that visibility was reduced to zero.

A survivor of the disaster is lifted from the ash by a helicopter. The rescue efforts have now been called off due to a high level of toxic gas emanating from the volcano

An injured hiker is carried into an ambulance in Kiso, Nagana after being airlifted out from the eruption zone

Pictured are mountain cottages and a shinto shrine on the volcano - all of which is covered in a deep layer of volcanic ash

Pictured left, rescuer workers carry an injured hiker off the slopes, while right, another is airlifted into a helicopter

Police confirmed the missing hikers have been found near the summit of the volcano in a state of cardiac arrest and are feared dead

Some 250 hikers were forced to run for their lives after Mount Ontake erupted yesterday lunchtime without any prior warning, covering the area in rock and ash

Seconds after the image left, visibility was reduced to almost zero as the walkers were engulfed in a cloud of volcanic dust and rock, right 

The ash cloud spread out immediately in every direction shooting thousands of feet into the sky before covering a two square mile area in dense, choking dust 

PYROCLASTIC FLOWS: A DEADLY AVALANCHE OF GAS AND ROCKS

This diagram shows how the pyroclastic flow works its way down the slope, reaching incredible speeds and leaving huge rock deposits in its wake

Pyroclastic flows are one of the most destructive and deadly processes of a volcanic eruption. The flows act and look like a body of liquid but are actually composed of hot gas and rock. Formed inside the volcano by the fragmentation of magma and rocks during the eruption, they travel down the mountain slope at breakneck speeds, often incinerating everything in their path.

The flows act as a fast-moving current and appear similar to a snow avalanche when they burst from the volcano. These flows, composed of volcanic rock debris and toxic gases, are usually deadly as they can reach speeds over 100 km/h and temperatures of 1,000 degrees.

Although they are composed of gas and rock, the properties of pyroclastic flows mean they act more like a liquid. The heavier debris moves along the ground, covered by a gas plume which radiates upwards as it moves. Depending on the size of the rock debris carried within them, they can leave behind deep layers of rock fragments.

The eruption at Mount Ontake likely triggered a pyroclastic surge, although it is thought to have been relatively cold when compared to some other documented flows.

Professor Emeritus of the University of Tokyo, Shigeo Aramak, told NHK World the colour of the debris clouds seen in the footage of the erupting Mount Ontake showed the temperature was relatively low for a pyroclastic flow, which may mean magma was not present.

Emergency services were initially unable to use helicopters in their rescue operations due to fears the helicopters would suffer catastrophic engine damage if they ingested the highly abrasive volcanic dust.

The 3,067 metre mountain is 230km west of Tokyo and has already forced airlines to divert aircraft from the area. Although the injured and trapped were being airlifted off the volcano today after flying conditions improved. 

One of the hikers was filming the mountain at the time of the eruption and captured some of the terrified walkers as they fled for their lives. 

Only a matter of seconds after hearing the noise, the cloud of abrasive dust closes in on them, blocking out the day light. As the cloud struck, the person holding the camera is forced to turn away from the onrushing dust and dive to the ground in order to breathe.

Ontake, Japan's second-highest volcano, last erupted seven years ago. Its last major eruption was in 1979.

Satoshi Saito, a 52-year-old hiker who climbed Ontake on Saturday and descended less than an hour before the eruption, said the weather was good and the mountain, known for its fall foliage, was crowded with people carrying cameras.

'There were no earthquakes or strange smells on the mountain when I was there,' Saito, who usually climbs Ontake several times a year, said. He also said there were no warnings of possible eruptions posted on the trail.

'But a man who runs a hotel near the mountain told me that the number of small earthquakes had risen these past two months, and everyone thought it was weird.'

A local fire brigade blocked roads towards Mount Ontake (pictured in the background), which is located 230km west of Tokyo

More than 250 people were on the mountain when the volcano started to erupt yesterday lunchtime forcing walkers to improvise protective masks 

Those near the bottom of the mountain were able to continue downwards, but an estimated 40 of those near the summit were stranded with seven reported missing 

The hiker's camera footage shows that instantly every exposed area in the mountain top is soon covered in the dust and people can be heard coughing and spluttering. 

Mikio Oguro, an NHK journalist who was on the slope on an unrelated assignment, told the station that he saw massive smoke coming out of the crater, blocking sunlight and reducing visibility to zero.

He said: 'Massive ash suddenly fell and the entire area was totally covered with ash,' he said by phone. He and his crew had to use headlights to find a lodge to take refuge.

'My colleagues later told me that they thought they might die.' 

Japan's meteorological agency raised the alert level for Mount Ontake to three on a scale of one to five. It warned people to stay away from the mountain, saying ash and other debris could fall up to 2.5 miles away.

One eyewitness told Japanese TV channel NHK: 'It was like thunder. I heard boom, boom, then everything went dark.' 

So far there has been no sign of any lava in the volcano, which last erupted in 2007, but scientists are monitoring the situation closely. Japanese prime minister Shinzo Abe returned earlier today from a visit to the US. He instructed the military to rescue the stranded hikers and remove them from the area in case the situation deteriorates further.

Mr Abe said: 'Nearly 200 people are in the process of descending the mountain, but we are still trying to figure out details. I instructed to do all we can to rescue the people affected and secure the safety of the trekkers.

Nagano police sent a team of 80 to the mountain to assist the climbers who were making their way down, while Kiso Prefectural Hospital, near the mountain, said it had dispatched a medical emergency team.

Volcanic ash has blanketed huge areas surrounding the summit of the volcano. Pictured, a helicopter and rescue workers work near the buildings

Rescuers said that 42 people were seriously injured while seven of those were rendered unconscious with a further seven reported missing since yesterday 

Japanese prime minister Shinzo Abe instructed the military to launch a rescue operation to escort the stranded walkers in case the situation deteriorates

Mount Ontake, pictured, began erupting round noon on Friday spewing rocks and ash over a two-mile radius of the mountain's summit

The 3,067 metre Mount Ontake is about 120 miles west of Tokyo and is popular with hikers and adventurous tourists looking for a walking holiday 

Walkers in the area were forced to improvise to protect themselves from the volcanic ash which was falling from the sky following yesterday's eruption 

A TV crew working in the area at the time of an unrelated story thought they were going to be killed when the ash and rocks began falling from the sky

A hospital official said: 'We expect a lot of injured people so we are now getting ready for their arrival.'

Mari Tezuka, who works at a mountain rescue hut on the mountain said: It's all white outside, looks like it has snowed. There is very bad visibility and we can't see the top of the mountain,

'All we can do now is shut up the hut and then we are planning on coming down... This is a busy season because of the changing autumn leaves. It's one of our busiest seasons.'

Scientists said there has not been any lava seen yet during this most recent event although Mount Ontake last erupted back in 2007 

Flights in and out of Tokyo have so far not been affected by the eruption, although local flight restrictions are in place

Poisonous gases and ash are being pumped thousands of feet into the sky as the volcano threatens to explode for the first time in almost a decade