Facing an unprecedented nuclear crisis, Japan on Sunday struggled hard to avert multiple meltdowns at two of its reactors damaged by the devastating earthquake and tsunami as it braced itself for a fresh explosion at the Fukushima plant amid fears that the toll may exceed 10,000 in the ravaged northeastern coast.
The International Atomic Energy Agency said excessive levels of radiation at the Onagawa nuclear power plant led authorities to report a state of emergency there.
“Japanese authorities have informed the IAEA that the first or lowest state of emergency at the plant has been reported by the Tohoku Electric Power Company,” the agency said.
It insisted, however, that, according to the authorities, the three reactor units at the plant “are under control.”
At the Tokai No 2 nuclear power plant, 120 km from Tokyo, a cooling pump failed but an additional pump was working and cooling the reactor, a plant spokesman said late in the night.
In southwestern Japan, the 1,421-metre Shinmoedake volcano erupted ringing alarm bells as ash and rocks shot up into the sky but it was not immediately clear if it was a fallout of the massive earthquake.
In a televised statement, Prime Minister Naoto Kan said Japan was experiencing its biggest crisis since World War II as it tackled the aftermath of the massive earthquake, the ferocious tsunami and the worrying nuclear crisis.
Meanwhile, thousands of military personnel and civilians joined hands in a massive search and rescue operation.
The Kyodo news agency said 1.80 lakh people were evacuated from a 20-km radius of the Fukushima nuclear plant. Already over 3.5 lakh people have already moved out of the region.
More than 2.15 lakh people are said to be living in 1,350 temporary shelters in five prefectures in quake-hit areas.
International disaster relief teams are being sent to Japan, with the U.N. helping to coordinate the operation.
The Japan government said it expected a “considerable” economic impact from the disaster.
Economists say it is still too early to assess the full cost of the destruction.
Leading risk analysis firm AIR Worldwide said the quake alone would exact an economic toll estimated at between $14.5 billion and $34.6 billion, without taking into account the effects of the tsunami.
The Bank of Japan plans to pump “massive” funds into markets on Monday in a bid to help them stabilise following the linked disasters, Dow Jones Newswires said.
Tokyo's benchmark Nikkei index is expected to tumble, with the index possibly breaking the psychologically important 10,000 level.
The quake and the tsunami have damaged or closed down key ports, although airports such as Tokyo's Narita have since reopened. Rail lines and roads have been crippled along parts of the northeast.
Many top Japanese firms have said they are suspending operations.
Millions are already without electricity, and Mr. Naoto said he had authorised a nationwide programme of planned power cuts to prevent any sudden major supply disruption. He appealed for public understanding.