Tokyo, January 13, 2007 - (DPA) An earthquake measuring 8.4 on the Richter scale struck northern Japan and a tsunami warning was issued early Saturday for Japan, Russia and the Marcus Islands.

Japanese authorities warned of a metre-high wave striking the western province of Wakayama and of upto 50-cm-high waves along the rest of the Pacific coast on Japan's northernmost island of Hokkaido, television station NHK reported.

The earthquake occurred at around 0423 GMT about 30 km under the surface of the Pacific Ocean.

In Abashiri city in Hokkaido, over 2,000 households were told to evacuate the area. Other coastal cities in the province of Iwate were also told to evacuate.

It was unclear whether a tsunami had been generated, but the warning was issued based on the size and location of the earthquake.