A strong 6.9 magnitude earthquake hit northeastern Japan early Tuesday, the USGS said, while Japanese authorities issued a tsunami warning for the region's coast including Fukushima prefecture.
A three meter (9.9 feet) tsunami could hit the northeastern coast, Japan's Meteorological Agency said, including Fukushima - home to the Fukushima Daiichi nuclear power plant, site of one of the world's worst nuclear disasters.
So far, several tsunami waves, the biggest measuring 90 centimeters (three feet) have hit the northeastern coast, public broadcaster NHK reported.
The United States Geological Survey (USGS) said the 6.9 magnitude quake, at a shallow depth of 11.3 kilometers (seven miles), struck shortly before 6 a.m. (2100 GMT on Monday) in the Pacific off Fukushima.
Japan's meteorological agency had earlier estimated the quake's magnitude at 7.3.
While the quake also shook buildings in Tokyo, there were no immediate reports of damage or injuries.
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Initial reports said there appeared to be no significant damage to the crippled Fukushima nuclear plant.
Japan sits at the junction of four tectonic plates and experiences a number of relatively violent quakes every year.
A massive undersea quake that hit in March 2011 sent a tsunami barrelling into Japan's northeast coast, leaving more than 18,000 people dead or missing, and sending three reactors into meltdown at the Fukushima nuclear plant.
In April, two strong earthquakes hit southern Japan's Kumamoto prefecture followed by more than 1,700 aftershocks, leaving at least 50 dead and causing widespread damage.
An announcer on public broadcaster NHK urged residents along the coast to move to high ground.
"Please flee immediately," the male voice said, with great urgency.
The vast majority of deaths in the 2011 disaster resulted from the tsunami, and NHK told viewers to heed the lessons of that day.
Photo: An aerial view shows the No. 3 reactor building at Tokyo Electric Power Co. (TEPCO)'s tsunami-crippled Fukushima Daiichi nuclear power plant in Fukushima Prefecture, in this photo taken by Kyodo July 18, 2013. Credit: Kyodo/via Reuters/File photo WATCH VIDEO: How A Tsunami Changed The Future Of Food