Experts said a total of 450 minor quakes have been registered over the past 24 hours near Karymsky, Kamchatka's most active volcano, in the southeast of the peninsular, which rises to 1,536 metres (5,039 feet) above sea level.
Satellite images show an ash plume 12 kilometers long and four kilometers wide, with a 100-km ash tail stretching southeastwards at a height of 3,500 meters (11,500 feet).
The volcano erupted in February following an 11-year period of normal activity. Ash emissions and about 230 minor tremors were reported last week. Experts say the volcano's activity has been accelerating.
This year more than 1,200 people, including 542 children, were evacuated from the north of the Kamchatka peninsula after a series of earthquakes. The first 7.8-magnitude quake, the strongest in the Koryak Autonomous Area in the north of the peninsular since 1900, injured 31 people on April 21. It also damaged about 380 houses and 25 administrative facilities in four other towns.