Tsunami warnings were lifted for Alaska and the rest of Pacific after a huge earthquake of 8.2 magnitude struck the US state.

In Alaska, small tsunami waves were observed in Sand Point, Old Harbor, King Cove, Kodiak, Unalaska and Alitak Bay, according to the US National Tsunami Warning Center (NTWC).

There were no immediate reports of injuries or damage to property.

Several Alaskan coastal communities were evacuated following the quake. Among them was Seward on the Kenai Peninsula, south of Anchorage, where sirens blared and residents were told to move to higher ground.

The US Geological Survey (USGS) said the quake, which struck at 10.15pm local time (6.15am Irish time, was at a depth of 35km. It struck about 91km east-southeast of Perryville, about 800km from Anchorage, Alaska's biggest city.

The US states of California, Oregon and Washington and the Canadian province of British Columbia were not expected to see any significant tsunami threats, Dave Snider, tsunami warning coordinator with the NTWC, said.

"There might be some minor damage in some places (in Alaska), but a significant tsunami and significant damage from something like that is not expected," he said.

While shallow earthquakes near populated areas can be dangerous, in this case the shallow quake posed less of a threat because they do not usually generate large tsunamis.

"That's really fortunate in this case, because 8.2 is really strong enough to make a sizable wave, especially in that location of the world," Mr Snider added.

The Pacific Tsunami Warning Center (PTWC) cancelled warnings issued for Hawaii and the US Pacific territory of Guam, while the public broadcaster NHK said there was no risk to Japan.

Authorities in New Zealand also said they did not expect any flooding in coastal areas.

According to the USGS, the quake was followed by over 25 aftershocks in the region, with two around magnitude 6.0.

A 7.5 magnitude earthquake caused tsunami waves in Alaska's southern coast in October, but no casualties were reported.

Alaska is part of the seismically active Pacific Ring of Fire.

The state was hit by a 9.2-magnitude earthquake in March 1964, the strongest ever recorded in North America. It devastated Anchorage and unleashed a tsunami that slammed the Gulf of Alaska, the US west coast, and Hawaii.

More than 250 people were killed by the quake and the tsunami in 1964.