A magnitude-6.5 earthquake hit off Japan's eastern coast early Thursday, the country's Meteorological Agency said.
There were no immediate reports of damage or casualties. The agency said there was no danger of damage from a tsunami.
The quake hit at 7:49 a.m. off the coast of Hachijo, a small island about 170 miles south of Tokyo, at a depth of 25 miles.
Japan is one of the world's most earthquake-prone countries, and experts believe Tokyo has a 90 percent chance of being hit by a major quake over the next 50 years.
In 1995, a magnitude-7.2 quake in the western port city of Kobe killed 6,400 people.