TOKYO, Feb. 28 (Xinhua) -- An earthquake with a preliminary magnitude of 5.6 struck off the coast of Fukushima Prefecture in Japan's northeast on Tuesday, the weather agency here said, although no tsunami warning has been issued.
According to the Japan Meteorological Agency (JMA), the offshore temblor occurred at 4:49 p.m. local time, at a latitude of 37.5 degrees north and a longitude of 141.4 degrees east.
The quake occurred at a depth of 50 km, the JMA said.
The powerful quake registered lower 5 on Japan's seismic scale which peaks at 7, in four towns in Fukushima Prefecture and in Iwanuma City in Miyagi Prefecture, in the Tohoku region of northern Japan.
In other regions in Fukushima, Miyagi, Aomori and Iwate prefectures, in the northeast of the country, the quake registered between 1 and 4 on Japan's seismic intensity scale.
In the nation's capital of Tokyo, the temblor registered 2 in some locations and also made the scale in Niigata and Shizuoka prefectures.
The magnitude-5.6 quake was followed by a Magnitude 4.6 quake at 5:08 p.m. local time, believed by the weather agency to be an aftershock.
The JMA has not issued a tsunami alert as a result of the quakes and no abnormalities were observed at the Onagawa nuclear power plant in Miyagi Prefecture, its operator said, according to local reports. \