Another fire at Japan's stricken Fukushima Daiichi nuclear power complex broke out early Wednesday, compounding the spree of disasters expected to take historic peacetime tolls on the nation's people and economy.
The latest blaze broke out in the No. 4 reactor at the nuclear complex on the northeast coast where a plume of radiation escaped Tuesday, sending background radiation levels soaring to degrees that authorities conceded were harmful to anyone with prolonged exposure.
With the confirmed dead and known missing topping 10,000 and untold thousands of others suspected to still be buried in the sodden wreckage littering the northeast shores of Honshu island, government leaders urged calm and patience as hardships persisted four days after the worst earthquake in Japan's recorded history.
The devastating tsunami that followed inflicted most of the damage half an hour after Friday's 9-magnitude quake, and a terrifying spate of fires, explosions and missteps at the nuclear power complex in Fukushima prefecture has intensified fears of another calamity.
Radiation released from the six-reactor Fukushima Daiichi complex Tuesday caused a 400-fold increase in background levels outside the stricken plant and about 10 times the normal level in Tokyo, the usually thriving capital 150 miles south of the power facility. Those levels described by a top government official as hazardous to human health declined overnight, suggesting the situation might be stabilizing at the three reactors experiencing cooling problems in the nuclear fuel containment vessels, officials said.
The latest fire, reported by Tokyo Electric Power Co. spokesman Hajimi Motujuku, compounded the woes besetting a skeleton crew of about 70 nuclear plant workers struggling to cool the damaged reactors and avert an uncontrolled release of radiation.
Radiation detected near the plant early Wednesday was insufficient to harm human health, Chief Cabinet Secretary Yukio Edano told reporters. He said they had also dropped to about twice the usual level in Tokyo, a negligible increase that posed no public hazard, he said.
Any risks posed by the emissions were eased by prevailing winds that carried the steam out to sea rather than over the populated inland, the national meteorological agency noted.
NHK television said 450,000 people remained in makeshift shelters outside the evacuated areas, down by about 100,000 from a day earlier as those made homeless by the earthquake and tsunami began making their way to less affected areas to stay with relatives and friends.
But authorities still struggled to get food, blankets and other relief to the displaced amid continuing road blockages and idled transport between Japan's major cities and the hard-hit agricultural and fishing areas of the northeast.
Three new earthquakes with a magnitude greater than 6.0 hit across a wide swath of Honshu on Tuesday, as well as more than a dozen that registered over magnitude 5.0, the U.S. Geological Survey reported.
Search and rescue teams from around the world scoured the wreckage of residential areas where the tsunami dumped tons of debris along miles of coastline. But the operations have ground down into a body retrieval exercise, with only two survivors reported to have been rescued by the massive undertaking Tuesday.
The international outpouring of help for Japan brought in 91 countries and at least a dozen multinational relief organizations, the Japanese Foreign Ministry reported. Most were concentrating on devastated Miyagi prefecture, deploying heavy lifting equipment to pry loose cars, trucks, boats and other objects from the rubble of wood and metal churned and scattered by the tsunami.
In Sendai, the city of 1 million closest to the earthquake's offshore epicenter, sleet began pelting the ravaged area overnight, a precursor to the snow and falling temperatures forecast for the rest of the week.
As economists began estimating the cost of the disasters, predicting they would exceed those inflicted by Hurricane Katrina in both money and lives, Tokyo's Nikkei index plummeted for a second day, losing another 10% of its value.