Tsunami warnings have been issues after a huge 7.5 magnitude earthquake struck off the coast of a Russian island.
The US Geological Survey said Wednesday's quake struck 135 miles south-east of Russia's Kuril Islands chain, north of Japan.
The Pacific Tsunami Warning Centre said hazardous tsunami waves were possible within 620 miles of the quake's epicentre.
It added earthquakes of this strength in the past have caused tsunamis far from the epicentre, and the US National Tsunami Warning Centre was analysing the event to determine the level of danger.
However, meteorological officials in Japan issued no alerts following the quake, although they said there might be slight tidal changes.
The US National Oceanic and Atmospheric Administration said a tsunami watch was issued for the state of Hawaii, while another agency, the Pacific Tsunami Warning Center, said the quake had potential to generate a destructive tsunami.
"Tsunami waves are forecast to be less than 0.3 meters above the tide level," the centre said in its advisory about risks to the coasts of Hawaii, Japan, Russia and the Pacific islands of Midway, the Northern Marianas and Wake Island.
The height is equivalent to just under a foot.
The Japan Meteorological Association warned against slight tidal changes but said no warnings or even watch advisories had been issued.
The earthquake, 218 km (135 miles) south-southeast of the town of Severo, struck at a depth of 56.7 km (35 miles), the U.S. Geological Survey (USGS) said.
There were no immediate reports of damage or casualties.
