A 6.8-magnitude earthquake struck off Japan's northeastern coast on Saturday but no tsunami warning was issued, Japanese and US authorities said, with no immediate reports of damage.
The United States Geological Survey (USGS) said the mid-morning quake hit at a depth of 47 kilometers (29 miles) in the Pacific, off Ishinomaki, Miyagi prefecture -- near the epicenter of a huge 2011 quake which triggered a towering tsunami, killing more than 18,000 people.
USGS and Japan's meteorological agency said there was no tsunami risk following the jolt, which produced strong shaking along parts of the eastern coast and was also felt in Tokyo.
Public broadcaster NHK said there were no immediate reports of damage.
Japan sits on the Pacific "Ring of Fire", an arc of intense seismic activity that stretches through Southeast Asia and across the Pacific basin.
The country is regularly hit by quakes, and has strict construction regulations intended to ensure buildings can withstand strong tremors. —Agence France-Presse