Powerful 7.6-magnitude earthquake strikes Japan's northeast region

A powerful magnitude 7.6 earthquake shook Japan's northeast region late on Monday, prompting tsunami warnings and orders for residents to evacuate.

The Japan Meteorological Agency (JMA) said a tsunami as high as three metres (10 feet) could hit Japan's northeastern coast after the earthquake struck at 11:15pm (1415 GMT).

Tsunami warnings were issued for the prefectures of Hokkaido, Aomori and Iwate, and tsunamis from 20 to 50cm (7 to 18 inches) high were observed at several ports, JMA said.

The epicentre of the quake was 80km (50 miles) off the coast of Aomori prefecture, at a depth of 50km (30 miles), the agency added.

On Japan's 1-7 scale of seismic intensity, the tremor registered as an "upper 6" in Aomori prefecture -- a quake strong enough to make it impossible to keep standing or move without crawling. In such tremors, most heavy furniture can collapse and wall tiles and windowpanes are damaged in many buildings.

East Japan Railway 9020.T suspended some services in the area, which was also hit by the massive 9.0-magnitude quake in March 2011.

No irregularities were reported at nuclear power plants in the region run by Tohoku Electric Power 9506.T and Hokkaido Electric Power 9509.T, the utilities said. Tohoku Electric did say, however, that thousands were without power.

Japan is one of the world's most earthquake-prone countries, with a tremor occurring at least every five minutes.

Located in the "Ring of Fire" of volcanoes and oceanic trenches partly encircling the Pacific Basin, Japan accounts for about 20% of the world's earthquakes of magnitude 6.0 or greater.