(Aol News)TOKYO -- A suspected breach in the core of a reactor at the stricken Fukushima nuclear plant could mean more serious radioactive contamination, Japanese officials revealed Friday, as the prime minister called the country's ongoing fight to stabalize the plant "very grave and serious."
A somber Prime Minister Naoto Kan sounded a pessimistic note at a briefing hours after nuclear safety officials announced what could be a major setback in the urgent mission to stop the plant from leaking radiation, two weeks after a devastating earthquake and tsunami disabled it.
"The situation today at the Fukushima Dai-ichi power plant is still very grave and serious. We must remain vigilant," Kan said. "We are not in a position where we can be optimistic. We must treat every development with the utmost care."
The uncertain situation halted work at the nuclear complex, where dozens had been trying feverishly to stop the overheated plant from leaking dangerous radiation. The plant has leaked some low levels of radiation, but a breach could mean a much larger release of contaminants.
Suspicions of a possible breach were raised when two workers waded into water 10,000 times more radioactive than is typical and suffered skin burns, the Nuclear and Industrial Safety Agency said.
Kan apologized to farmers and business owners for the toll the radiation has had on their livelihoods: Several countries have halted some food imports from areas near the plant after milk and produce were found to contain elevated levels of radiation.
The prime minister also thanked utility workers, firefighters and military personnel for "risking their lives" to cool the overheated facility.
The alarm Friday comes two weeks to the day since the magnitude-9 quake triggered a tsunami that enveloped cities along the northeastern coast and knocked out the Fukushima reactor's cooling systems.
Police said the official death toll jumped past 10,000 on Friday. With the cleanup and recovery operations continuing and more than 17,400 listed as missing, the final number of dead was expected to surpass 18,000.