While relief efforts continued Monday for survivors of the earthquake and tsunami that devastated Japan's northeast, the country's meteorological agency warned of the possibility of a 7.0 or higher magnitude temblor in the coming days.

According to the agency, there is a 70 per cent chance of another quake in the next three days and a 50 per cent chance of another hitting three days after that because of high tectonic activity.

Meanwhile, the country is racing to prevent a humanitarian disaster as rescue workers struggle to reach tens of thousands of people left homeless by the 9.0 earthquake and tsunami.

Japanese officials raised the estimated death toll to more than 10,000 Sunday, as hundreds of thousands of survivors salvaged what belongings they could, sought food and water at emergency centres and spent three nights in near-freezing temperatures.

Friday's quake and tsunami damaged key nuclear plants and left entire cities demolished in their wake.

So far, the number of confirmed dead is 1,647, with 1,720 missing across the affected areas in the east and northeast. But thousands more are still missing, and the confirmed number is expected to increase significantly after a report that some 2,000 bodies were found Monday on two shores in Miyagi.

Kyoto News Agency reports that about 1,000 bodies were found coming ashore on Miyagi's Ojika Peninsula. Another 1,000 bodies were spotted in the town of Minamisanriku where about 10,000 people, which is over half the local population, are still missing.  

The official death toll also excludes about 200 to 300 bodies in Miyagi's capital, Sendai. Police and other workers are unable to reach these bodies amid the devastation and rubble.

Meanwhile, an estimated 1.4 million households were still without water Monday, and at least 1.9 million homes did not have electricity. Officials in one devastated town said they were running out of body bags.

Japanese Prime Minister Naoto Kan called the disaster the worst crisis since World War II, and appealed in a television address for the Japanese people to come together to rebuild.

While the official death toll may not be known for days, or weeks, CTV's Tom Walters, speaking from Narita, Japan, said locals on the ground have little doubt that the death toll is much higher than the estimates being released by officials.

"There really is so much destruction, so many areas of debris that are difficult to search, so many areas were we are told rescuers have yet to reach," Walters told CTV News Channel on Sunday. "I don't think there is any confidence here on a full accounting for the human toll of this disaster."