Japanese engineers rush to avert radiation leak from damaged nuclear reactor in a battle to avert a looming disastrous meltdown as rescuers frantically search for thousands of missing persons and assist millions without food, water, shelter or heating after a powerful quake and tsunami hit Japan.

One reactor at the Fukushima nuclear power plant was damaged by the powerful quake which triggers an explosion Monday exposing fuel rods after water levels dropped rapidly. Smoke billowing from the complex can be seen from afar but the United Nations nuclear watchdog dismissed fear the tragedy in Japan could repeat the Chernobyl nuclear disaster in Russia.

Patrick Fuller of the International Red Cross Federation from the northeaster coastal town of Otsuchi described the scene, "It's a scene from hell, absolutely nightmarish."

Rescue workers were overwhelmed by the destruction as they struggle to reach the tsunami-battered region north of the capital Tokyo where early estimates put the number of deaths at 10,000 following the 8.9 magnitude quake and the tsunami that followed it.

The tragedy is considered the worst to hit Japan since World War II as the financial cost of calamities is estimated to reach up to $180 billion. Many financial analysts fear the quake can set the world's third largest economy back into recession.

On Tuesday, the Japanese stock markets retreated more than 7.5 percent which wiped off at least $287 billion off market capitalization, the biggest decline since the global financial crisis in the middle of 2008. Elsewhere in the world, stocks fell in London and New York as the global financial system absorbed the impact of the devastations in Japan.

At the Fukushima nuclear complex some 240 kms north of Tokyo, experts are trying to avert a major radiation leak after the quake and tsunami destroyed its cooling systems. At least two explosions have been recorded at two of the complex's reactors on Saturday and Monday. But authorities are confident the risk of radiation is minimal.

The damaged nuclear complex revived fears after the worst nuclear accident in Chernobyl in Ukraine in 1986. It also triggered fresh debate about the safety of nuclear power.

But Yukiya Amano, head of the International Atomic Energy Agency, dismissed fears of another Chernobyl disaster and said the reactor vessels of nuclear power plants affected by the disaster remained intact and, so far, the amount of radiation that had been released was limited.

Amano said in a statement, "The Japanese authorities are working as hard as they can, under extremely difficult circumstances, to stabilize the nuclear power plants and ensure safety," and added that it was "unlikely that the accident would develop" like Chernobyl.

The Swiss government reacted swiftly and put on hold approvals for nuclear plan applications while Germany announced plans to scrap a proposal to extend the use of its nuclear power plants. In the Philippines, proponents of nuclear energy abandoned their positions. However, U.S. President Barack Obama said his administration remains committed to nuclear energy.

Early estimates put some 859,000 people in the north were without electricity and in near-freezing condition as the Tohuku Electric Power Co., said at least 1.5 million households were without water.

The missing person number to tens of thousands government and search and rescue officials said.

Fuller told Reuters, "The situation here is just beyond belief, almost everything has been flattened. The government is saying that 9,500 people, more than half of the population, could have died and I do fear the worst."

Kyodo news agency reported that 2,000 bodies had been found on Monday in two coastal towns alone.