TOKYO (AP) - A strong earthquake has struck north-eastern Japan, but the authorities say there is no danger of a tsunami, and there were no immediate reports of casualties.

The Japan Meteorological Agency said Sunday's (Aug 4) quake had a preliminary magnitude of 6.2.

The epicentre was off the north-eastern coast of Japan, about 50km below the seabed.

The quake shook a wide area of the region, including Fukushima and Miyagi prefectures.

Public broadcaster NHK TV says utility companies are checking on the nuclear reactors in the area.

In 2011, Fukushima was hit by a powerful quake, tsunami and nuclear meltdown, the worst nuclear disaster since Chernobyl.