An earthquake with a magnitude of 6.9 on the Richter scale hit eastern Japan on Wednesday, the Japan Meteorological Agency said.
There were no immediate reports of casualties and damage. No tsunami warning was issued for the 9:19 a.m. (0019 GMT) quake. The tremor was also felt in Tokyo.
The operator of the crippled Fukushima Daiichi nuclear plant said there were no signs of abnormalities at the facilities from the quake. Shinkansen bullet train service in the region was briefly suspended to confirm safety, but resumed afterwards.
The focus of the tremor was offshore near Torishima Island, about 580 km south of Tokyo, at a depth of 400 km. The quake measured 4 on the Japanese seismic scale of 7 in more than 20 municipalities, according to the agency.
It defines an intensity of 4 as capable of causing dishes and objects in shelves to rattle. The Japanese scale measures how much places were shaken on the surface while the Richter scale measures the energy of the quake itself.
Japan, located in a zone where the Eurasian, Pacific, Philippine and North American tectonic plates meet and occasionally shift, is hit by 20 percent of the world's earthquakes of magnitude six or greater. The country was severely damaged by the magnitude 9.0-quake and ensuing tsunami that left nearly 19,000 people dead or missing in March 2011