A strong earthquake centred off the coast of northeastern Japan shook buildings as far as Tokyo and led to a tsunami warning for coastal areas of the northeast, public broadcaster NHK says.
The earthquake had a preliminary magnitude of 7.3, the U.S. Geological Survey said, adding that there was no risk of a widespread tsunami. That was revised from an earlier estimate of 7.4.
A warning for a one-metre tsunami was issued for the coast of Miyagi Prefecture in northeastern Japan, which was hit by a devastating earthquake and tsunami in March 2011.
That quake triggered fuel-rod meltdowns at the Fukushima nuclear plant, causing radiation leakage, contamination of food and water and mass evacuations in the world's worst nuclear crisis since Chernobyl in 1986.
The government declared in December that the disaster was under control, but much of the area is still free of population.
Tokyo Electric Power Co, the operator of the Fukushima nuclear plant, reported no irregularities at its nuclear plants after the latest quake.