"It will take at least three days to remove most of the rubble before starting reconstruction," said Hideto Yamamoto, a city hall official. "We also have to consider measures to support those who suffered damage."

The government sent in 110 troops -- known as the Self-Defense Forces due to Japan's post-World War II pacifist constitution -- at the request of local authorities, the Defense Agency said.

They joined 90 local officials working to clear up the small town.

Meanwhile more strong wind gusts Thursday hit Okushiri, a small island 20 kilometers (12 miles) off Hokkaido's west coast, damaging at least eight buildings. No one was injured, officials and local media said.

"We received a report that a strong gust occurred around noon today and caused damage to some houses," said an official of Okushiri Fire Department.

According to Jiji Press, two warehouses were destroyed and six residential houses were partially damaged, with two electricity polls pulled down as wind gusts ripped through the island.

Tornados -- known in Japan as "tatsumaki" or "spiralling dragons" -- are relatively rare in the archipelago, which is routinely hit by typhoons and earthquakes.

In 1993, Okushiri fell victim to a major earthquake that triggered a massive tsunami, killing 200 people.

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A world of storm and tempest