A 7.5 magnitude earthquake struck near Russia's far eastern Kuril Islands and a tsunami warning was issued for the closest shores.
The U.S. Geological Survey said the quake struck south-southeast of Severo on the Kuril chain north of Japan. It was 56 kilometres (37 miles) deep.
The Pacific Tsunami Warning Center said hazardous tsunami waves were possible within 1,000 kilometres of the quake's epicenter.
It said earthquakes of this strength in the past have caused tsunamis far from the epicenter, and the U.S. National Tsunami Warning Center was analyzing the event to determine the level of danger.