One of the strongest earthquakes ever recorded struck Russia's sparsely populated Far East early on Wednesday, causing tsunamis up to four metres across the Pacific and sparking evacuations from Hawaii to Japan.

In Japan, nearly two million people were advised to evacuate, and many left by car or on foot to higher ground.

A 1.3-metre high tsunami reached a port in the northern prefecture of Iwate, Japan's weather agency said. But there were no injuries or damage reported by early afternoon.

At Inage Beach in Chiba prefecture, a security perimeter was set up, and a rescue worker saidthe seaside area was off limits until further notice.

Workers at the stricken Fukushima nuclear plant in northeast Japan – destroyed by a huge quake and tsunami in 2011 – were evacuated, its operator said.

The magnitude 8.8 quake struck in the morning off Petropavlovsk on Russia's remote Kamchatka peninsula and was one of the 10 biggest recorded, according to the US Geological Survey (USGS).

A video posted on Russian social media showed buildings in the town submerged in seawater. Authorities said the population of around 2,000 people was evacuated.

Several people were injured in Russia by the quake, state media reported, but none seriously.

Authorities in Russia's far eastern Sakhalin region declared a state of emergency in the northern Kuril Islands. The mayor there said everyone was evacuated to safety.

Officials from countries with a Pacific coastline in North and South America – including the United States, Mexico and Ecuador – issued warnings to avoid threatened beaches.

In Hawaii, Honolulu mayor Rick Blangiardi said residents and the thousands of visitors should get to safety on upper floors of buildings or higher ground.

"People should not, and I will say it one more time, should not, as we have seen in the past, stay around the shoreline or risk their lives just to see what a tsunami looks like," governor Josh Green said. "It is not a regular wave. It will actually kill you if you get hit by a tsunami."

Wednesday's quake was the strongest in the Kamchatka region since 1952, the regional seismic monitoring service said, warning of aftershocks of up to 7.5 magnitude.

The epicentre of the earthquake is roughly the same as the massive 9.0 temblor that year which resulted in a destructive, Pacific-wide tsunami, according to the USGS.

In December 2004, a 9.1 magnitude earthquake struck off the Indonesian island of Sumatra, triggering a tsunami that killed around 220,000 people in 11 nations.

The US Tsunami Warning Centers said waves exceeding three metres above the tide level were possible along some coasts of Ecuador, northwestern Hawaiian islands and Russia.

Between one- and three-metre waves were possible along some coasts of Chile, Costa Rica, French Polynesia, Hawaii, Japan and other islands in the Pacific, it said.

Waves of up to one metre were possible elsewhere, including Australia, Colombia, Mexico, New Zealand, Tonga and Taiwan. (AFP)