A very powerful magnitude 8.8 earthquake off Russia's Far Eastern Kamchatka coast Wednesday triggered tsunami warnings as far away as French Polynesia and Chile, and was followed by an eruption of the most active volcano on the peninsula.

The shallow quake damaged buildings and injured several people in the remote Russian region, while much of Japan's eastern seaboard — devastated by a 9.0 magnitude earthquake and tsunami in 2011 — was ordered to evacuate, as were parts of Hawaii. By the evening, Japan, Hawaii and Russia had downgraded most tsunami warnings. But authorities in French Polynesia warned residents of several of the remote Marquesas Islands to move to higher ground and expect waves as high as 8 feet.

Russian scientists said the quake in Kamchatka was the most powerful to hit the region since 1952. The US Geological Survey said it was shallow, at a depth of 19.3 km.

Kremlin spokesman Dmitry Peskov said there had been no casualties in Russia.

The Klyuchevskoy volcano on Russia's Kamchatka Peninsula began erupting later, a geological monitoring service said.

Hawaii recorded waves of up to 1.7 metres while in Japan the largest recorded came to 1.3 metres, officials said.

Waves of nearly half a metre were observed as far away as California, with smaller ones reaching Canada's province of British Columbia.

Authorities in Ecuador's Galapagos Islands, some 970 km off South America's western coast, ordered precautionary evacuations to safe zones.

Kamchatka and Russia's Far East sit on the Pacific Ring of Fire, a geologically active region that is prone to earthquakes and volcanic eruptions.