An emergency services worker looks at a kindergarten damaged by an earthquake, in Petropavlovsk-Kamchatsky, Kamchatka Krai, Russia, July 30, 2025 in this screen grab from handout video. Photo: Reuters
In a statement posted on Telegram, the Russian Academy of Sciences' United Geophysical Service said: "A descent of burning hot lava is observed on the western slope. Powerful glow above the volcano, explosions."
Located around 450 km (280 miles) north of the regional capital, Petropavlovsk-Kamchatsky, Klyuchevskoy is one of the highest volcanoes in the world.
It has erupted several times in recent years.
Wednesday's 8.8 magnitude quake off Kamchatka damaged buildings and injured several people in the remote Russian region, but no fatalities were reported.
