Small tsunami waves hit northern and eastern Japan yesterday after a powerful earthquake in the Pacific prompted tsunami warnings in Japan, Russia and Alaska.

Watches were also mounted in Guam, Taiwan, the Philippines and Hawaii, island territories nervous of a repeat of the disaster two years ago when a quake in the Indian Ocean created giant waves that killed 230,000.

A 40 cm wave was reported at Chichijima in the Ogasawara islands, some 1,200 km south of Tokyo, and several smaller waves on Hokkaido and northern Japan, but there were no reports of injuries and no immediate reports of damage.

Evacuation advisories had been issued for tens of thousands of households in Japan but all warnings were cancelled at 10.10 p.m.

The USGS (US Geological Survey) put the quake magnitude at 8.2, a "great" tremor, and said its epicentre was in the northern Pacific, 525 km east northeast of Kurilsk, Kurile Islands, and 1,710 km northeast of Tokyo.

The same area was struck by a powerful quake in November, prompting evacuations and tsunami warnings, but then too only small waves reached Japan. An official in Russia's Emergencies Ministry told Reuters the threat of a tsunami had passed.

Japan's Meteorological Agency had said a tsunami as tall as a metre could hit parts of Hokkaido and smaller waves were likely to hit a wide area of coast, from Hokkaido to Wakayama prefecture on Japan's largest main island of Honshu. Hokkaido officials urged residents to move to higher ground and fire trucks made the rounds of coastal areas warning about the tsunami threat. There were only moderate tremors in Hokkaido and no immediate reports of casualties.