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.

Alerts for a potential tsunami were issued for coastlines in North America, Hawaii, Russia and Japan after a powerful 8.8-magnitude earthquake struck in the North Pacific Ocean off Russia’s northern Pacific coast, according to the U.S. Tsunami Warning System, which is part of the National Weather Service.

A tsunami has hit coastal areas of Russia’s Kuril Islands and Japan’s large northern island of Hokkaido after an 8.7-magnitude earthquake early on Wednesday. Tsunami warning sirens sounded in Honolulu, Hawaii, where people were told to move to higher ground.