TOKYO (Reuters) - The biggest earthquake to hit Japan on record struck the northeast coast on Friday, triggering a 10-metre tsunami that swept away everything in its path, including houses, ships, cars and farm buildings on fire.
The Red Cross in Geneva said the wall of water was higher than some Pacific islands and a tsunami warning was issued for almost the entire Pacific basin.
At least 44 people had been killed in the quake and tsunami in Japan, broadcaster NHK said, adding that many were missing. The extent of the destruction along a lengthy stretch of Japan's coastline suggested the death toll could rise significantly.
The 8.9 magnitude quake, the most powerful since Japan started keeping records 140 years ago, caused many injuries and sparked fires while the tsunami prompted warnings to people to move to higher ground in coastal areas.
"The earthquake has caused major damage in broad areas in northern Japan," Prime Minister Naoto Kan told reporters.
Some nuclear power plants and oil refineries were shut down and a refinery was ablaze.
Around 4.4 million homes were without power in northern Japan, media said. A hotel collapsed in the city of Sendai and people were feared buried in the rubble.
A ship carrying 100 people had been swept away by the tsunami, Kyodo news agency added.
Electronics giant Sony Corp (6758.T), one of the country's biggest exporters, shut six factories, as air force jets raced toward the northeast coast to determine the extent of the damage.
The Bank of Japan, which has been struggling to boost the anaemic economy, said it would do its utmost to ensure financial market stability as the yen and Japanese shares fell.
"I was terrified and I'm still frightened," said Hidekatsu Hata, 36, manager of a Chinese noodle restaurant in Tokyo, where buildings shook violently. "I've never experienced such a big quake before."
The Philippine and Indonesia issued tsunami alerts, reviving memories of the giant tsunami which struck Asia in 2004. The Pacific Tsunami Warning Center issued alerts for countries to the west and across the Pacific as far away as Colombia and Peru.
The earthquake was the fifth most powerful to hit the world in the past century.
There were several strong aftershocks. In Tokyo, there was widespread panic. An oil refinery near the city was on fire, with dozens of storage tanks under threat.
"People are flooding the streets. It's incredible. Everyone is trying to get home but I didn't see any taxis in Ginza, where there are usually plenty," said Koji Goto, a 43-year-old Tokyo resident.
TV footage showed a muddy wall of water carrying debris across a large swathe of coastal farmland near the city of Sendai, which has a population of one million. Ships in once coastal area were lifted from the sea into a harbour where they lay helplessly on their side.
Sendai is 300 km (180 miles) northeast of Tokyo and the epicentre at sea was not far away.
NHK television showed flames and black smoke billowing from a building in Odaiba, a Tokyo suburb, and bullet trains to the north of the country were halted. Thick smoke was also pouring out of an industrial area in Yokohama's Isogo area. TV showed residents of the city running out of shaking buildings, shielding their heads with their hands from falling masonry.
TV footage showed boats, cars and trucks tossed around like toys in the water after a small tsunami hit the town of Kamaichi in northern Japan. An overpass, location unknown, appeared to have collapsed and cars were turning around and speeding away.
Kyodo said there were reports of fires in Sendai where waves carried cars across the runway at the airport.
"The building shook for what seemed a long time and many people in the newsroom grabbed their helmets and some got under their desks," Reuters correspondent Linda Sieg said in Tokyo. "It was probably the worst I have felt since I came to Japan more than 20 years ago."
The U.S. navy said its ships had been unaffected by the tsunami and were ready to provide disaster relief if needed. China offered to provide earthquake relief.
The quake struck just before the Tokyo stock market closed, pushing the Nikkei down to end at a five-week low. Nikkei futures trading in Osaka tumbled as much as 4.7 percent in reaction to the news.
The disaster also weighed on markets elsewhere.
The quake was the biggest since records began 140 years ago, according to the Japan Meteorological Agency. It surpasses the Great Kanto quake of September 1, 1923, which had a magnitude of 7.9 and killed more than 140,000 people in the Tokyo area.
The 1995 Kobe quake caused $100 billion in damage and was the most expensive natural disaster in history. Economic damage from the 2004 Indian Ocean tsunami was estimated at about $10 billion.
Passengers on a subway line in Tokyo screamed and grabbed other passengers' hands during the quake. The shaking was so bad it was hard to stand, said Reuters reporter Mariko Katsumura.
Hundreds of office workers and shoppers spilled into Hitotsugi street, a shopping street in Akasaka in downtown Tokyo.
Household goods ranging from toilet paper to clingfilm were flung into the street from outdoor shelves in front of a drugstore.
Crowds gathered in front of televisions in a shop next to the drugstore for details. After the shaking from the first quake subsided, crowds watched and pointed to construction cranes on an office building up the street with voices saying, "They're still shaking!", "Are they going to fall?"
Asagi Machida, 27, a web designer in Tokyo, sprinted from a coffee shop when the quake hit.
"The images from the New Zealand earthquake are still fresh in my mind so I was really scared. I couldn't believe such a big earthquake was happening in Tokyo."
The U.S. Geological Survey earlier verified a magnitude of 7.9 at a depth of 15.1 miles and located the quake 81 miles east of Sendai, on the main island of Honshu. It later upgraded it to 8.9.
Japan's northeast Pacific coast, called Sanriku, has suffered from quakes and tsunamis in the past and a 7.2 quake struck on Wednesday. In 1933, a magnitude 8.1 quake in the area killed more than 3,000 people.
Earthquakes are common in Japan, one of the world's most seismically active areas. The country accounts for about 20 percent of the world's earthquakes of magnitude 6 or greater. (Writing by John Chalmers and Miral Fahmy; Tokyo bureau and Asia Desk, Editing by Dean Yates)