A magnitude 6.6 earthquake struck near the coast of the Kamchatka region in the far east of Russia on Sunday, the German Research Centre for Geosciences (GFZ) said.
The quake was at a depth of 10 km (6.21 miles), GFZ said. It initially reported a magnitude of 6.2 for the earthquake.
A separate earthquake measuring 6.7 magnitude struck off the east coast of Kamchatka at a depth of 10 km, shortly following the previous quake, according to GFZ data.
The European Mediterranean Seismological Centre (EMSC) shows the second earthquake to be of 7.4 magnitude.
Tsunami warning issued for Hawaii and Alaska
Northeastern Russia was hit by a series of strong earthquakes, with four tremors exceeding a magnitude of six recorded within an hour. The most powerful quake measured 7.4 on the Richter scale.
Following the earthquakes, US authorities issued a tsunami warning for the states of Hawaii and Alaska. Aftershocks continue to rattle the region, raising concerns of further seismic activity.
Authorities are closely monitoring the situation, while residents in the affected areas have been urged to stay alert for any emergency advisories.
