Sendai, Japan:
More than 70,000 people fled vulnerable coastal areas of Japan Sunday as a tsunami churned up by the huge earthquake in Chile slammed into the country's long Pacific coastline.
"Please do not approach the coast at any cost," Prime Minister Yukio Hatoyama said in nationally televised comments as Japan, one of the world's most quake-prone nations, went on its first major tsunami alert in 15 years.
The first tsunami wave, 30 centimetres high, hit Nemuro on the northern island of Hokkaido in the early afternoon, the Meteorological Agency said.
Far bigger waves of up to three metres could hit northern areas of Aomori, Iwate and Miyagi prefectures, south of Hokkaido, the agency said.
Hatoyama urged extreme caution even as fears of destructive waves eased across the rest of the Pacific.
"We should not drop our guard," the sombre-looking prime minister said. "I would like people to take all possible measures."
The Meteorological Agency also issued warnings for waves of up to two metres along the entire Pacific coastline of the Japanese archipelago, from Hokkaido through to the southern island chain of Okinawa.
Tsunami warnings flashed across all television channels as authorities rushed at least 70,000 people living on Japan's east coast to schools and other public facilities located on higher ground.
Evacuation sirens wailed across the archipelago. Massive steel gates slammed shut across the entrances to several fishing ports and coastguard vessels fanned out to search for stray ships still at sea.
Officials in northern Japan said more than 50,000 residents had been ordered to evacuate, while many regional railway services were halted and public broadcaster NHK issued non-stop warnings to people to take shelter.
"We have not witnessed any panic among residents, but we are trying hard to work on a smooth evacuation," said Shigeru Suzuki, a local official in the northeastern city of Sendai.
Masanori Kitamura, an official at Hachinohe on the northern tip of Japan's main island Honshu, said: "Now, our firefighters are patrolling out there to check whether any residents remain near the coast."
Saturday's quake in Chile, which killed at least 300 people, revived raw memories for Japan.
In 1960, a 9.5-magnitude earthquake in Chile - the largest on record - sent a tsunami hurtling across the Pacific, leaving more than 140 people dead in Japan.
However, construction standards and safety drills have vastly improved and Japan is today a world leader in disaster preparedness.
"Last time (in 1960), waves that hit after the first one became even more powerful," said Yasuo Sekita, a Meteorological Agency official in charge of monitoring earthquakes and tsunamis.