Nearly a week after a record 9.0-magnitude earthquake shook Japan, bringing a devastating tsunami to its eastern shore, the number of dead or missing has surpassed the 10,000 mark.

Kyodo News reported the increased numbers following Friday's powerful earthquake, as a new 6.4-magnitude temblor hit Shizuoka prefecture southeast of Tokyo, rattling the capital.

The news agency reported Tuesday that the new death toll marks the first time since 1923, when the Great Kanto Earthquake struck, that a natural disaster has killed more than 10,000 people in Japan.

However, some incredible stories of survival are still emerging from Japan, and about 25,000 people have been rescued.

On Tuesday a man in his 20s was pulled alive from the rubble, 94 hours after the quake, after a two-storey house collapsed around him.

Two hours later a 75-year-old woman was rescued, suffering from hypothermia but otherwise uninjured.

The stories of hope following the devastation are far outweighed by the mounting death toll, however.

Japan's National Police Agency said Tuesday the number of confirmed dead was at 3,373, Kyodo News reported. And another 6,746 were missing.

On top of that, hundreds, if not thousands of bodies have been washing up on Japan's northeast coast, many of them still unidentified. The total death toll is expected to rise to 10,000.

And four days after the earthquake and tsunami, it's believed that 6,000 people are still without shelter, food, water and heat -- many of them in isolated areas still entirely cut off from the outside world.

Around 1,300 people were found on the island of Oshima, in Miyagi prefecture, Kyodo News reported. Another 7,000 to 8,000 people had taken shelter in schools but had still not received any supplies.

Japanese Prime Minister Naoto Kan called it the greatest crisis the country has faced since the Second World War.

Friday's earthquake has also left millions with little food or shelter, as temperatures drop to near-freezing levels overnight. Hospitals are overwhelmed with the injured and running out of medicine and supplies.

More than 440,000 people are spending their nights at 2,400 shelters in central and northeastern Japan, Kyodo reported, with some suffering from food and water shortages.

In Iwate prefecture, one of the most devastated areas of Japan, government official Hajime Sato said only 10 per cent of needed supplies had been delivered.

Authorities were also running out of coffins to bury the dead.

In neighbouring Fukushima prefecture, officials say the town of Soma is at least one-third flooded and thousands of residents are missing. The local crematorium was unable to handle the large number of bodies.

"We have already begun cremations, but we can only handle 18 bodies a day. We are overwhelmed and are asking other cites to help us deal with bodies. We only have one crematorium in town," Katsuhiko Abe, an official in Soma, told The Associated Press.

CTV's Lisa LaFlamme reported from Narita that due to the rising death toll, the Japanese government has waived a rule that requires citizens to get approval from their local officials before they cremate or bury a body.

"The current situation is so extraordinary, and it is very likely that crematoriums are running beyond capacity," said Health Ministry official Yukio Okuda.

"This is an emergency measure. We want to help quake-hit people as much as we can."

Rescue workers were trying to recover up to 300 bodies in Sendai, the capital of Miyagi. Another 8,000 people in Otsuchi, in Iwate prefecture, are said to be unaccounted for.

Indonesian geologist Hery Harjono said Japan's death-toll projection was too conservative. He told The Associated Press it would be "a miracle really if it turns out to be less than 10,000."

Harjono noted that many victims may have been pulled out to sea, as happened when the 2004 tsunami struck Indonesia's Aceh province. About 230,000 people died in Indonesia, but only 184,000 bodies were ever found.