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, U.S. 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 US 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.