A powerful earthquake struck central Japan on January 1, destroying scores of buildings, knocking out power to tens of thousands of homes and prompting residents to evacuate some coastal areas.
The quake with a preliminary magnitude of 7.6 triggered waves of about 1 metre along Japan's west coast and South Korea, with authorities saying larger waves could follow.
I total, more than 30 earthquakes struck between 4pm and 7.30pm.
The Japan Meteorological Agency (JMA) issued tsunami warnings for the prefectures of Ishikawa, Niigata and Toyama. A major tsunami warning was initially issued for Ishikawa but later downgraded. Russia also issued tsunami warnings for some areas.
Houses have been destroyed, fires have broken out and army personnel have been dispatched to help with rescue operations, a government spokesperson told reporters, adding that authorities were still assessing the damage.
More strong quakes in the area, where seismic activity has been simmering for more than three years, could occur over coming days.
More than 36,000 households had lost power in Ishikawa and Toyama prefectures, areas where temperatures where set to drop to near freezing overnight, according to utilities provider Hokuriku Electric Power. Telecoms operators also reported phone and internet outages in some areas.
