The U.S. Geological Service map shows the epicenter of a major earthquake east of Japan on Oct. 25, 2013.
A magnitude 7.3 earthquake struck off the Fukushima region of Japan, according to the U.S. Geological Service.
The epicenter was located 231 miles east of Japan's Honshu Island at a depth of 6 miles. The tremor was felt 300 miles away in Tokyo.
It prompted a tsunami advisory covering more than 200 miles along Japan's east coast, stretching from the northern edge of Iwate Prefecture to the southern tip of Chiba Prefecture.
USA TODAY reporter William Welch said he was asleep in a Tokyo hotel room when the earthquake woke him up around 3:10 a.m. Saturday local time.
Welch, who has felt many earthquakes while at his home in California, said Saturday's earthquake varied in intensity and "seemed to be the longest one I've experienced."
The Japan Meteorological Agency issued a tsunami warning at 1:14 p.m. EST for Fukushima Prefecture.
"Marine threat is in place," the agency warns. "Get out of the water and leave the coast immediately. As the strong current will continue, do not get in the sea or approach coasts until the advisory is cleared."
The warning has been expanded to include Iwate, Miyagi, Ibaraki, and Chiba Prefectures.
The agency said it expects a slight sea level change in coastal regions, but no tsunami damage.
NOAA's Pacific Tsunami Warning Center said the quake was not expected to trigger a Pacific-wide tsunami and that there was no threat to Hawaii.
There were no immediate reports of injuries or damage. Nor were any irregularities reported at the Fukushima Dai-ichi nuclear power plant, about 160 miles northeast of Tokyo. which was hit by a 2011 tsunami triggered by a quake off the Japanese coast. About 19,000 people were killed in that disaster.
All but two of Japan's 50 reactors have been offline since the magnitude-9.0 earthquake and tsunami led to multiple meltdowns and massive radiation leaks at the plant.
Contributing: Donna Leinwand Leger