It is the first organised ascent of the volcano in the last 30 years.
Maintaining communication with rescuers, the group of ten mountaineers traversed the safest slope, taking samples of volcanic rock and ash en route.
They all have undergone a special training and each had a 6,000-dollar insurance.
Seismic stations around the 3,283-metre-tall Shiveluch are registering series of quakes, up to 1.5-kilometre-high gas and vapour eruptions from the crater.
A powerful eruption was registered on May 10: ash blow-outs reached ten kilometers above the crater, incandescent lava flowed down the slope. The regional board of the Emergency Situations Ministry closed the volcano and the adjacent territory to visitors.
Since Shiveluch eruptions are explosive, its cupola can be destroyed. This poses a grave danger for the populated places and communications at its foot. Mud flows from its slopes have many times washed off the Klyuchi-Ist-Kamchatsk highway.
Catastrophic eruptions happen once in 100 to 300 years. The recent ones were registered in 1854 and 1964.
