Tokyo: Japan confronted devastation along its northeastern coast on Saturday, with fires raging and parts of some cities under water after a massive earthquake and tsunami that likely killed at least 1,000 people.
Daybreak was expected to reveal the full extent of the death and damage from Friday's 8.9 magnitude earthquake and the 10-meter high tsunami it sent surging into cities and villages, sweeping away everything in its path.
In one of the worst-hit residential areas, people buried under rubble could be heard calling out "help" and "when are we going to be rescued," Kyodo news agency reported.
The government warned there could be a small radiation leak from a nuclear reactor whose cooling system was knocked out by the quake. Prime Minister Naoto Kan ordered an evacuation zone around the plant be expanded to 10 km (6 miles) from 3 km. Some 3,000 people had earlier been moved out of harm's way.
Underscoring concerns about the Fukushima plant, 240 km (150 miles) north of Tokyo, US officials said Japan had asked for coolant to avert a rise in the temperature of its nuclear rods, but ultimately handled the matter on its own. Officials said a leak was still possible because pressure would have to be released.
The unfolding natural disaster prompted offers of search and rescue help from 45 countries.
China said rescuers were ready to help with quake relief while President Barack Obama told Japanese Prime Minister Naoto Kan the United States would assist in any way.
"This is likely to be a humanitarian relief operation of epic proportions," Japan expert Sheila Smith of the US-based Council on Foreign Relations wrote in a commentary.
The northeastern Japanese city of Kesennuma, with a population of 74,000, was hit by widespread fires and one-third of the city was under water, Jiji news agency said on Saturday.
The airport in the city of Sendai, home to one million people, was on fire, it added.
TV footage from Friday showed a muddy torrent of water carrying cars and wrecked homes at high speed across farmland near Sendai, 300 km (180 miles) northeast of Tokyo. Ships had been flung onto a harbor wharf, where they lay helplessly on their side.
Boats, cars and trucks were tossed around like toys in the water after a small tsunami hit the town of Kamaichi in northern Japan. Kyodo news agency reported that contact had been lost with four trains in the coastal area.
Japanese politicians pushed for an emergency budget to fund relief efforts after Kan asked them to "save the country," Kyodo news agency reported. Japan is already the most heavily indebted major economy in the world, meaning any funding efforts would be closely scrutinized by financial markets.
Domestic media said the death toll was expected to exceed 1,000, most of whom appeared to have drowned by churning waters.
The extent of the destruction along a lengthy stretch of coastline suggested the death toll could rise significantly.
Even in a nation accustomed to earthquakes, the devastation was shocking.
"A big area of Sendai city near the coast, is flooded. We are hearing that people who were evacuated are stranded," said Rie Sugimoto, a reporter for NHK television in Sendai.
"About 140 people, including children, were rushed to an elementary school and are on the rooftop but they are surrounded by water and have nowhere else to go."
Japan has prided itself on its speedy tsunami warning system, which has been upgraded several times since its inception in 1952, including after a 7.8 magnitude quake triggered a 30-meter high wave before a warning was given.
The country has also built countless breakwaters and floodgates to protect ports and coastal areas, although experts said they might not have been enough to prevent disasters such as the one that struck on Friday.
In Tokyo, many residents who had earlier fled swaying buildings slept in their offices after public transport was shut down. Many subways in Tokyo later resumed operation but trains did not run.
"I was unable stay on my feet because of the violent shaking. The aftershocks gave us no reprieve. Then the tsunamis came when we tried to run for cover. It was the strongest quake I experienced," a woman with a baby on her back told television in northern Japan.
The quake, the most powerful since Japan started keeping records 140 years ago, sparked at least 80 fires in cities and towns along the coast, Kyodo said.
Other Japanese nuclear power plants and oil refineries were shut down and one refinery was ablaze.
Auto plants, electronics factories and refineries shut, roads buckled and power to millions of homes and businesses was knocked out. Several airports, including Tokyo's Narita, were closed and rail services halted. All ports were shut.
The central bank said it would cut short a two-day policy review scheduled for next week to one day on Monday and promised to do its utmost to ensure financial market stability.
The disaster occurred as the world's third-largest economy had been showing signs of reviving from an economic contraction in the final quarter of last year. It raised the prospect of major disruptions for many key businesses and a massive repair bill running into tens of billions of dollars.
The tsunami alerts revived memories of the giant waves that struck Asia in 2004.
Warnings were issued for countries to the west of Japan and across the Pacific as far away as Colombia and Peru, but the tsunami dissipated as it sped across the ocean and worst fears in the Americas were not realised.
The earthquake was the fifth most powerful to hit the world in the past century.
"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 quake 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.
Earthquakes are common in Japan, one of the world's most seismically active areas.