A powerful 8.2-magnitude earthquake rocked the northern Pacific on Saturday, prompting warnings for thousands of Japanese to flee for higher ground before tsunami fears eased as only small waves hit the coast.
The United States cancelled an earlier tsunami alert for Russia, Japan, Taiwan, Guam and other smaller Pacific islands issued after the huge tremor off the Russian-controlled Kuril Islands at about 0954 IST (0424 GMT).
The Pacific Tsunami Warning Centre also withdrew a tsunami watch for a vast part of the Pacific basin including the Philippines, Vietnam, Indonesia, Papua-New Guinea and Hawaii.
The Japanese meteorological agency, which originally estimated the quake's magnitude at 8.3 but lowered it later, downgraded its tsunami warnings to advisories by early evening and will continue to monitor the situation.
Earlier, as Japans emergency response system swung into action, evacuation advisories were issued to tens of thousands of coastal residents.
In Tokyo, the government set up a special communication office to collect information about possible tsunamis.
But fears of injury or damage soon eased as only small waves reached the shores of northern Japan after the huge quake, which briefly revived memories of the Indian Ocean tsunami of December 2004 that killed some 2,20,000 people.
The biggest tsunami to hit Japan by early evening was observed at the small island of Chichijima, which saw waves as high as 40 centimetres starting at 4:56 pm (1426 IST), but caused no damage.