The epicenter was about 40 km under water off Miyagi Prefecture.

Tsunami sirens wailed in the northeastern area of the country immediately after the quake.

It was reported that serious jolt lasted for one minute in Sendai and it was felt in Tokyo more than 300 km away from the epicenter.

The quake left two persons dead and at least 100 wounded as of April 8.

It brought nuclear power plants and thermal power stations to the suspension of operation, caused fires in different places, train service to a halt and left 4 million households in Iwate and Aomori prefectures and other places without the supply of electricity.

Damage is predicted to steadily increase.

The above-said quake is considered to be aftershock of massive earthquake which occurred on March 11, the Japan Meteorological Agency said, predicting that aftershock of over 7.0-magnitude may occur in the future.