The US Geological Survey measured the quake at 6.5 magnitude and said it was 404 kilometres deep.
In March 2011, a magnitude 9.0 earthquake offshore of northeastern Japan, and ensuing tsunami, killed more than 18,000 people and devastated the coastline for hundreds of miles. It also crippled the Fukushima Dai-ichi nuclear power plant, causing meltdowns in three of its reactors.
Japan's Nuclear Regulation Authority said no abnormalities were reported at Fukushima and two other nuclear plants in northern Japan that were shaken by today's quake.
The eastern-central region of Japan is said to be due for a major quake and smaller temblors are common.
- AP