Millions of Americans are under threat of a tsunami after a massive earthquake has struck off the coast of Russia.
Preliminary data from the US Geological Survey shows the quake reached a magnitude of 8.7 and struck about 84 miles east-southeast of Kamchatska at around 7.24pm EST.
A tsunami warning is now in effect for parts of Alaska's Aleutian Island and Hawaii, while a tsunami watch has expanded to cover the entire West Coast of the United States.
Oahu Emergency Management has since urged residents on the coast to evacuate the area.
Authorities at the Pacific Tsunami Warning Center have warned that 'a tsunami may have been generated by this earthquake that could be destructive' to coastal areas.
