An earthquake has struck off Japan's northeast coast, triggering a tsunami warning.
The Japanese Meteorological Agency said the August 19 quake had a preliminary magnitude of 6.8. It struck at a depth of 20 kilometers off the coast.
There were no immediate reports of damage.
Waves of up to 50 centimeters were forecast to hit areas along the northeast coast including where the Fukushima Daiichi nuclear plant is situated.
The plant's reactors were severely damaged in the 9.0 magnitude earthquake and tsunami on March 11.
compiled from agency reports