Fears of a major meltdown at Japan’s Fukushima Daiichi are continuing to grow after plant officials found highly radioactive water near another reactor at the nuclear plant, two weeks after a massive earthquake and tsunami crippled the complex.

Safety officials in Japan blamed the spike in radiation levels on a possible break in the core of one of the plant’s nuclear reactors, which could have leaked large amounts of radioactive material.

From The Guardian:

The prime minister, Naoto Kan, described the situation at the plant as "very serious", while media reports said that two men who were injured while working on the plant's No.3 reactor on Thursday may have suffered internal exposure to radiation.

"We must remain vigilant," Kan told a televised news conference. "We are doing our best to prevent a deterioration in the situation, but we are not yet in a position that allows us to be optimistic. We must treat every development with the utmost care."

He praised the hundreds of Tokyo Electric Power employees, troops, firefighters and police officers who are struggling to avert disaster at the plant, and insisted any new information would be released quickly to the Japanese people and the international community.

"We have been transparent right from the start and will continue to give accurate information about radiation levels and their possible impact on health," he said.

The heightened levels of radiation around the plant was the latest setback in Japanese efforts to contain a nuclear meltdown or leakage from the damaged plant. Now, the government is taking precautions by widening the voluntary evacuation zone around the nuclear facility.

Bloomberg reported:

The spokesman’s comments came as the Japanese government advised people who live within 20 to 30 kilometers (12.4 to 18.6 miles) of the plant to leave voluntarily, although a Kyodo report said the move was prompted by logistical problems in getting daily necessities rather than safety concerns.

In addition, plant workers working near reactor No. 3 on Thursday were exposed to levels of levels of radiation much higher than normally found in the Fukushima reactor.

From Reuters:

But fresh fears were raised on Thursday when three workers trying to cool the most critical reactor were exposed to radiation levels 10,000 times higher than normally found in a reactor. Two of them suffered radiation burns when contaminated water seeped over their shoes.

The high level of contamination raised the possibility of a leak of radioactive material through a crack in the core's container which would mean a serious reversal following slow progress in getting the plant under control.

The reactor, the No. 3 unit, is the only one to use plutonium in its fuel mix which is more toxic than the uranium used in the other reactors.

The official death toll from the earthquake and the tsunami that struck the island country two weeks ago has risen above 10,000 people and more than 17,000 are still reported missing.