The death toll in Japan's earthquake and tsunami will likely exceed 10,000 in one state alone, an official said on Sunday, as millions of survivors were left without drinking water, electricity and proper food along the pulverized northeastern coast.

Although the government doubled the number of soldiers deployed in the aid effort to 100,000, it seemed overwhelmed by what's turning out to be a triple disaster.

Friday's quake and tsunami damaged two nuclear reactors at a power plant on the coast, and at least one of them appeared to be going through a partial meltdown, raising fears of a radiation leak.

The police chief of Miyagi prefecture, or state, told a gathering of disaster relief officials that his estimate for deaths was more than 10,000, police spokesman Go Sugawara told The Associated Press.

Miyagi has a population of 2.3 million and is one of the three prefectures hardest hit in Friday's disaster. Only 379 people have officially been confirmed as dead in Miyagi.

The nuclear crisis posed fresh concerns for those who survived the horrors of Friday's earthquake and tsunami, which hit with breathtaking force and speed, breaking or sweeping away everything in its path.

"First I was worried about the quake, now I'm worried about radiation. I live near the plants, so I came here to find out if I'm OK. I tested negative, but I don't know what to do next," Kenji Koshiba, a construction worker, said at an emergency center in Koriyama town near the power plant in Fukushima.

According to officials, at least 1,000 people were killed — including 200 people whose bodies were found Sunday along the coast — and 678 were missing in the disasters.

The U.S. Geological Survey calculated the initial quake to have a magnitude of 8.9, while Japanese officials raised their estimate on Sunday to 9.0. Either way it was the strongest quake ever recorded in Japan. It has been followed by hundreds of powerful aftershocks.

Teams searched for the missing along hundreds of miles (kilometers) of Japanese coastline, and hundreds of thousands of hungry survivors huddled in darkened emergency centers that were cut off from rescuers and aid.

At least 1.4 million households had gone without water since the quake struck and some 2.5 million households were without electricity.