Light tsunami hit Japan's Pacific coast on the main island of Honshu and coastal areas of Hokkaido Wednesday night after a strong earthquake with a preliminary magnitude of 8.1 off Hokkaido of northern Japan.

Tsunami of 40-centimeter wave and 20-cm wave hit Hokkaido's east coast at 9:29 p.m. and 9:43 p.m. respectively, Kyodo News reported.

Some areas in Aomori and Iwate prefectures in the Tohoku region and in Chiba Prefecture in the Kanto region were hit by 10-20 cm waves, according to the Japan Meteorological Agency.

The agency issued a tsunami warning right after the quake, whose center was 390 kilometers off the disputed Etorofu Island near Hokkaido of northern Japan, happened at 8:15 p.m.

The warning has expected waves of between one and two meters to hit Hokkaido's north and east coasts from about 9:10 p.m. and waves of 50 centimeters to hit the Pacific coast of Honshu by around midnight.

The Japanese government set up an emergency liaison office at Prime Minister Shinzo Abe's official residence to deal with the incident.

Local municipalities in Hokkaido ordered more than 80,000 residents in coastal areas to evacuate, and no immediate reports of injuries or damage has been reported across Japan, according to TV reports.

Etorofu is one of the four islands claimed by both Russia and Japan. They are called the Northern Territories by Japan and known as the southern part of the Kuril Islands in Russia.

Editor: Yan