One of the most powerful earthquakes in modern history shook Russia’s remote east coast Wednesday, sending tsunami waves hurtling across the Pacific Ocean and putting nations from Japan to the United States to Chile on high alert with millions urged to evacuate.

Hours after a powerful earthquake struck off Russia's Kamchatka Peninsula, the region's highest volcano began erupting. Geophysicists from the Russian Academy of Sciences reported a strong glow visible at the summit of the 4,750-metre Klyuchevskoy volcano in the Russian Far East.

Officials from Japan to California issued warnings after an 8.8-magnitude quake off Russia’s coast. Hours later, there were no immediate reports of major damage, although some areas remained on alert.