Japan's Meteorological Agency has lifted a tsunami warning for the country's northeastern coast.
The warning was issued after a magnitude 7.3 quake struck offshore, swaying buildings across much of Japan. There were no immediate reports of serious damage but several people were reportedly hurt.
One coastal city reported that a tsunami of three feet hit about 45 minutes after the quake.
Shortly before the earthquake struck, NHK television broke off regular programming to warn that a strong quake was due to hit. The country's Meteorological Agency has an early warning system using data from seismographs scattered across Japan. Afterward, the announcer repeatedly urged all near the coast to flee to higher ground.
Tokyo Electric Power says there have been no problems at any of its nuclear plants.