An earthquake with a preliminary magnitude of 6.0 jolted the Tohoku region and surrounding areas Saturday afternoon, the Meteorological Agency said. No tsunami warning was issued.
On the Japanese seismic scale to 7, the 2:48 p.m. quake, which originated off Fukushima Prefecture at a depth of about 46 km, registered upper 5 in Ishinomaki, Miyagi Prefecture, and 4 in several parts of Miyagi as well as Fukushima, according to the agency.
Ishinomaki was one of the areas hard hit by the March 11, 2011, megaquake and tsunami.
So far no injuries have been reported, Miyagi police and firefighters said.
The agency believes the latest earthquake was an aftershock of the 2011 temblor.
"Aftershock activities have become less frequent but we urge the public to be careful, since there are also unusually strong aftershocks like this one (today)," an agency official said.
The quake caused no abnormalities at the Fukushima No. 1 and No. 2 nuclear power plants or the Onagawa plant in Miyagi Prefecture, according to the utilities that operate them.
Sendai airport briefly suspended flights to check the runways, while train services on the Tohoku Shinkansen Line were partially stopped for about six minutes, carriers said.