- 100,000 troops lead the rescue and recovery efforts
- Evacuations ordered following new tsunami warnings
- Nuclear reactor suffers partial meltdown, agency says
- Official death toll in the hundreds
SENDAI, Japan — Millions of people were without drinking water, electricty or adequate food Sunday as the death toll from a devastating earthquake and tsunami was climbing along Japan's northeast coast.
Japan's government ordered 100,000 troops to join the rescue and recovery effort after thousands of survivors huddled over heaters in emergency shelters through a second freezing night.
Adding to the country's woes, radiation was leaking from an unstable nuclear reactor in Fukushima prefecture, near Sendai.
Japan's nuclear safety agency reported that radioactive cesium and iodine were detected near the facility Saturday. The detection of the materials, which are created during atomic fission, prompted the company to acknowledge that the reactor's fuel had partially melted, Japan's Kyodo news agency reported. The reactor also was rocked by an explosion on Saturday, but authorities said the blast did not damage the containment structure surrounding the reactor.Video: Meltdown fears at damaged nuclear reactor (on this page)
Japan's Meteorological Agency said it had upgraded the magnitude of Friday's catastrophic earthquake to 9.0. The agency earlier measured it at 8.8.
The quake was already the biggest to hit Japan since record-keeping began in the late 1800s and one of the biggest ever recorded in the world. The U.S. Geological Survey measured the quake at 8.9.
Aerial footage from the hardest-hit areas showed buildings and trains strewn like children's toys after powerful walls of seawater swamped areas around the worst-hit city of Sendai, about 100 miles from the earthquake's epicenter.
Teams searched for the missing along hundreds of miles of the coast, and 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.
Large areas of the countryside were surrounded by water and unreachable. Fuel stations were closed and people were running out of gasoline for their cars.
Public broadcaster NHK said around 380,000 people have been evacuated to emergency shelters, many of them without power.
In Iwanuma, not far from Sendai, nurses and doctors were rescued Saturday after spelling S.O.S. on the rooftop of a partially submerged hospital, one of many desperate scenes. In cities and towns across the northeast, worried relatives checked information boards on survivors at evacuation centers.
Helicopters also plucked survivors from an elementary school in Sendai.
100,000 troops dispatched
The government doubled the number of troops ordered into the rescue and recovery operations to 100,000.
''First and foremost, we need to make full efforts in saving lives and rescuing people,'' Prime Minister Naoto Kan said.
The military forces were helping evacuate survivors from the quake-damaged area, with about 300,000 relocated so far, according to Kyodo.Map: Japan earthquake (on this page)
The scale of destruction was overwhelming, with grim signs that the death toll — officially in the hundreds — could soar. A police official in Miyagi said another 200 bodies were found Sunday. One report said four whole trains had disappeared Friday and still had not been found. Others said 9,500 people in one coastal town were unaccounted for.
Atsushi Ito, an official in Miyagi prefecture, among the worst-hit states, could not confirm that, noting that with so little access to the area, thousands of people in scores of towns could not be contacted.
Early Sunday, firefighters had yet to contain a large blaze at the Cosmo Oil refinery in the city of Ichihara. Four million households remained without power. The Russian news agency RIA Novosti reported that Japan had asked for additional energy supplies from Russia.
New evacuations ordered
Government officials also ordered new evacuations in several coastal areas as they warned that aftershocks may trigger new tsunamis. Residents were told to head for higher ground.
More than 150 aftershocks — including a 6.8 temblor just before noon Saturday — followed Friday's massive quake. Another, Sunday morning, a 6.2 earthquake centered just 111 miles east of Tokyo at a depth of 15.2 miles, swayed buildings in the capital.Video: Scale of Japanese disaster reveals grim equation (on this page)
President Barack Obama pledged U.S. help following what he called a potentially "catastrophic" disaster. One U.S. aircraft carrier is already in Japan and a second was on its way, he said. A U.S. ship also was also heading to the U.S.-owned Marianas Islands to assist, he added.
The situation in Sendai, one of the cities nearest to the epicenter of the earthquake, which occurred about 80 to 100 miles offshore, was particularly grim.
"Everything is so hard now," said Kumi Onodera, a 34-year-old dental technician in Sendai, who described the quake and tsunami that quickly followed as being "like a scene from a disaster movie."
"The road was moving up and down like a wave. Things were on fire and it was snowing," she said. "You really come to appreciate what you have in your everyday life."
Weary, mud-spattered survivors wandered streets strewn with fallen trees, crumpled cars, even small airplanes. Relics of lives now destroyed were everywhere — half a piano, a textbook, a soiled red sleeping bag.Video: Shattered Sendai spends another night in darkness (on this page)
Rescue workers rode boats through murky waters around flooded structures, nosing their way through a sea of detritus, while smoke from at least one large fire billowed in the distance. Power and phone reception was cut, while hundreds of people lined up outside the few still-operating supermarkets for basic necessities. The gas stations on streets not covered with water were swamped with people waiting to fill their cars.
Slideshow: Devastation in Japan after quake (on this page)
To the south of Sendai, in Iwaki city, many area residents spent the night outdoors, or wandering debris-strewn streets, unable to return to homes damaged or destroyed by the quake or tsunami. Those who did find a place to rest for the night awoke to scenes of utter devastation.
The city's Wakabayashi district, which runs down to the sea, remained a swampy wasteland with murky, waist-high water. Most houses were completely flattened, as if a giant bulldozer had swept through.
In Iwaki town, residents were leaving due to concerns they over dwindling food and fuel supplies. The town had no electricity and all stores were closed. Local police had taken in about 90 people and given them blankets and rice balls but there was no sign of government or military aid trucks.
In the small town of Tagajo, near the hard-hit port city of Sendai, dazed residents roamed streets cluttered with smashed cars, broken homes and twisted metal.
Supplies running low
In districts around Fukushima, survivors lined up for drinking water in town centers, filling teapots and plastic containers.
Surreal and desperate scenes were commonplace: Off Japan's northeastern coast, an oil tanker lay eerily stranded in shallow water. Inland, in Sendai, a black minivan perched perilously on a metal post.
In Tokyo, which lies about 300 miles from the epicenter and where many have long feared the prospect of another monster earthquake of the scale of one that killed about 140,000 people in 1923, residents struggled to come to terms with damage inflicted on the country and their city.Interactive: Japan earthquake aftershocks (on this page)
Some were relieved the damage in the capital was not greater — in great part due to stringent building codes — but many remained panic-stricken about the continuing chaos.
"People make manuals for earthquakes, but when the earthquake actually happens, can you actually follow the manual?" said 60-year-old officer worker Kiyoshi Kanazawa.
"Everyone runs away when things are shaking, and they ask you to stop the gas and fire in your house, but you do not have enough space for this in your brain."
Msnbc.com staff, the Associated Press and Reuters contributed to this report.