A strong earthquake with a preliminary magnitude of 5.6 shook northeastern Japan on Sunday, the Meteorological Agency said. There were no immediate reports of injuries or damage.
The temblor was centered 30 km beneath the seabed off the coast of Fukushima Prefecture.
The agency said there was no danger of tsunami.
An earthquake of magnitude 5 or higher can cause damage to homes and buildings if it occurs in a populated area.