VLADIVOSTOK - The aviation alert code for Klyuchevskoy Volcano in Russia's Kamchatka Peninsula has been raised from orange to red following intensified eruptive activity, local authorities said on Thursday.

In a statement published on its Telegram channel, the Kamchatka Volcanic Eruption Response Team (KVERT) of the Institute of Volcanology and Seismology of the Far Eastern Branch of the Russian Academy of Sciences said a summit explosive-effusive eruption is currently underway, with satellite data showing ash rising up to 9.5 km above sea level and ash plume drifting some 141 km east-southeast of the volcano.

KVERT warned that ash explosions up to 10 km above sea level could occur at any moment, which would potentially affect international and low-flying aircraft in the region.

Standing at about 4,754 meters, Klyuchevskoy is the highest active volcano in Eurasia.

Summit eruptions have intensified following a massive 8.8 magnitude earthquake off the Kamchatka Peninsula last week.