tsunami warning in japan

The first tsunami wave, 30 centimetres high, hit Nemuro on Japan's northern Hokkaido island and there were reports of a second, 90 centimetre wave in Iwate prefecture.

Tsunami sirens were activated and massive steel gates shut across the entrances to several fishing ports as warnings of a large wave of up to three metres were broadcast across northern Japan.

The meteorological agency said that although the initial waves were quite small, larger ones may follow.

"Depending on the location, it is possible that waves higher than the ones observed at tidal stations have arrived," the agency said.

"It is possible that tsunami waves will grow bigger."

Prime Minister Yukio Hatoyama warned people not to approach the coast, even as fears of destructive waves eased across the rest of the Pacific.

"Please do not approach the coast at any cost," a sombre-looking Hatoyama said in nationally televised comments.

"We should not drop our guard. I would like people to take all possible measures."

In 1960, a tsunami caused by a large earthquake in Chile killed 140 people in Japan.

Warnings lifted

Meanwhile, tsunami warnings across the Pacific are being lifted as the threat passes.

Russia has cancelled warnings after 25 centimetre waves hit parts of its Pacific coast.

Russia had warned that a two-metre tsunami could hit its far east Kuril Islands about 3:00pm (AEDT) on Sunday, and dozens of people were evacuated from their coastal homes.

People in Hawaii were urged to evacuate to higher ground, but the tsunami threat has since past there.

Beaches on Australia's east coast were closed today as smaller waves hit the coast.

Gerard Fryer, a geophysicist at the Pacific Tsunami Warning Centre in Hawaii, said the waves were generally much smaller than had been feared.

"We had a full coastal evacuation in Hawaii and the waves here were quite a bit smaller than expected," he said.

"The reason is that the earthquake didn't extend all the way to the trench, the deepest water off Chile, so it was in shallower water and that meant there was less water to move and so the initial tsunami was somewhat small