Experts said Mount Karymsky, in the southeast of the peninsular, which rises to 1,536 metres (5,039 feet) above sea level, spewed ash emissions up to an altitude of around 3,600 meters, although a precise evaluation was made difficult by the volcano's remoteness from detection equipment.
Satellite images show a dust cloud, currently about 120 km to the east of Mount Karymsky.
The volcano last erupted in February following an 11-year period of normal activity. An observatory in Alaska then reported a 15-kilometer ash plume stretching from the volcano eastwards, at a height of 4,000 meters.
Two short quakes, each measuring 5.0 on the Richter scale, were also registered late Tuesday in Far East Russia's Amur Region, bordering on China, a spokesman said. No damage was caused by the tremors.
The largest major disaster was on May 28, 1995, when over 2,000 people were killed when an earthquake devastated the town of Neftegorsk on the island of Sakhalin.
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 since 1900, injured 31 people on April 21 and had an epicenter about 30 kilometers (18 miles) from the town of Khailino. It also damaged about 380 houses and 25 administrative facilities in four other towns.
