An earthquake of magnitude 7.1 struck near the east coast of Russia's Kamchatka region on Saturday, the German Research Centre for Geosciences (GFZ) said.
According to GFZ, the quake was at a depth 10 kilometres.
The United States Geological Survey (USGS) pegged the magnitude at 7.4, with a depth of 39.5 km.
The Pacific Tsunami Warning System said there was a threat of a tsunami.
In Japan, to the southwest of the Kamchatka Peninsula, no tsunami warning has been issued, broadcaster NHK reported, citing the Japan Meteorological Agency.

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