An earthquake measuring 6.0 on the Richter scale hit near the east coast of Japan's Honshu island Wednesday, the Hong Kong Observatory said.
The epicentre of the temblor that struck at 2.33 GMT was initially determined to be near 35.2 degrees north latitude and 141.4 degrees east longitude, about 150 km southeast of Tokyo city.
There were no immediate reports of casualties or damage to property.
Last year, a deadly 9.0-magnitude earthquake and tsunami that hit the area March 11 had left almost 20,000 dead or missing.