Eight climbers have died in an accident while ascending the highest active volcano in Asia, Klyuchevskaya Sopka.
The group of 10 Russian climbers with two guides had sent a plea for help on Saturday.
A helicopter with a rescue team was on the way to the site of the accident, Russian emergency officials said.
The volcano -- at a height of 4,750 metres -- is located in Russia's far eastern Kamchatka peninsula, a region known for hot springs and abundant wildlife.
Early reports said five climbers had been killed when they fell off a cliff and one other person was injured and knocked unconscious.
On Sunday morning, the head of the regional government told state media that another person had died, bringing the death toll to six. By the evening, however, he reported that two more people had died, bringing the total to eight.
The Kamchatka Territory regional emergency service stated that a helicopter carrying rescuers was unable to land on the Klyuchevskoy volcano on Sunday due to hurricane-force winds.
Another rescue group of 24 people is climbing to an altitude of 1,200 metres, where they plan to set up a base camp to provide assistance to the rescue team members making the ascent and the injured