TOKYO • Eight teenagers from a high school mountaineering club died in an avalanche in an area of north-eastern Japan that had been blanketed by unusually heavy spring snows, the authorities said.

The students were training about 120km north of Tokyo, in an area where the weather bureau had issued an avalanche warning urging caution a day earlier.

Dozens of other students and teachers were injured after the avalanche hit at about 9.20am yesterday.

"Suddenly, everything turned white," a male student who was caught by the cascade of snow said in a telephone interview with NHK, the Japanese national broadcaster.

"The teacher at the front yelled 'get down', so we dropped down and got covered in snow," said the student, who was not identified by name.

"Then those of us who could move helped dig out people who were buried," he added.

About 60 students from seven high schools in rural Tochigi prefecture were participating in the annual early-spring climb in Nasu.

The area has been in the grip of snowstorms strong enough that rescue helicopters initially had trouble reaching the avalanche zone, according to Japanese news reports.

Television news footage showed rows of ambulances and other emergency vehicles waiting in the still-falling snow as crews worked to find and rescue survivors.

Prime Minister Shinzo Abe spoke of the disaster in Parliament, saying that officials were "making every effort to respond".

After several hours, rescuers began bringing down the bodies of the dead, covered in blue plastic tarps.

The branch of the Tochigi government responsible for dealing with natural disasters identified the victims as boys from Otawara High School.

Otawara has one of the top school mountaineering clubs in this mountain-filled country, having won the Tochigi prefectural title for competitive climbing eight years running, according to its website.

Survivors said members of the Otawara club were leading several groups of students during a trekking exercise on a low-altitude slope when the avalanche struck.

About 40 participants suffered injuries, all but two of them minor, the authorities said.

Officials from the Tochigi board of education said at a news conference that the group of seven schools had originally planned to climb to the top of the 1,915m Chausudake mountain, to cap a three-day training programme that began on Saturday.

The group had been camping at a ski resort near the mountain's base, the officials said, learning lessons on how to climb in the snow, including how to avoid avalanches.

But conditions worsened starting on Sunday night, with a storm that brought high winds and more than 30cm of new snow, according to the Tochigi branch of the Japanese national weather service.

So instead of climbing the mountain as planned, the board of education said, teachers decided to have the students practise trekking on the much lower - and presumably safer - slopes around the ski resort.

Prefectural officials said that about a dozen students stayed behind because they lacked the confidence or equipment to move through the deep snow.

"I heard yelling. Then afterwards, I heard the sound of sirens and helicopters," one student, who was in a tent about 90m from the avalanche, told NHK.

"I couldn't contact some of my friends for a few hours," he said. "I learnt how scary a mountain can be."

NYTIMES