As darkness fell over northern Japan on Monday and thousands of survivors of a string of earthquakes prepared to spend a third night in emergency shelters, or in the open air, fear of more tremors was palpable.
"People are traumatized," said Naoki Kokawa, relief division director of the Japanese Red Cross. "More than 80,000 people have fled their homes and many are afraid to return. They know there's a chance of another big one."
Already 25 people have died and perhaps more than 2,000 have been injured in coastal Niigata prefecture since a first earthquake -- measuring 6.8 on the Richter scale -- struck on Saturday night.
With Ojiya city as its epicentre, it flattened houses, precipitated landslides, tore open roads, brought down overpasses and rocked buildings as far away as Tokyo, 260 kilometres to the southeast. A Shinkansen bullet train heading from the capital to Niigata was derailed although miraculously none of the passengers were injured.
Aftershocks continued through Sunday and another powerful quake measuring 5.6 occurred this morning causing more damage.
Coming within days of the country's worst typhoon in a quarter of a century, these tremors were the most deadly since 1995 when the city of Kobe was devastated. More than 240 shocks had been registered by this morning, most of them minor but among a number of serious tremors that followed the initial quake were one of 6.2 and another of 5.9.
The affected region has suffered widespread power and gas cuts, and disruption of the water supply as mains were torn open. The injured have overwhelmed some hospitals, and casualties have been treated in makeshift wards in corridors.
The full extent of the disaster was still emerging today. Some communities have been cut off by landslides or damage that has left roads impassable, and although military helicopters have assisted relief efforts, concern was being voiced this morning for people who remain isolated.
Some 600 were known to be caught in the Niigata village of Yamakoshi, more in the Tarusawa and Shionomata areas of Tokamachi municipality. The damage there still had to be assessed.
What bothered people huddling in emergency shelters was a warning from Japan's Meteorological Agency that there was a ten per cent chance of more tremors above six on the Richter scale occurring within a few days.
"Some people feel going home is like playing Russian roulette. Some feel safer in the open," a source in Ojiya said.
But with temperatures plummeting the Japanese Red Cross was concerned. "It's getting very cold now," said Naoki Kokawa. "Night-time temperatures can be close to zero. Keeping people warm, particularly children and elderly, is a priority, along with the provision of food, water and sufficient sanitation. The longer this goes on the greater the challenges."
The Japanese Red Cross was still helping thousands of survivors of deadly floods and landslides unleashed by typhoon Tokage last week when it launched an earthquake operation on Saturday.
While the 750-bed Nagaoka Red Cross hospital in Niigata opened its doors for the injured, Red Cross hospital disaster relief teams were deployed by Tokyo, Saitama, Toyama, Niigata, Tochigi and Gunma chapters, and by the Japanese Red Cross Medical Centre at national headquarters.
The relief teams of doctors, nurses, pharmacists and other specialists are running mobile health clinics at emergency shelters in schools and public buildings in Ojiya, Tokamachi and Nagaoka, and providing psychological support for the traumatized.
Meanwhile, a special disaster response unit dispatched from Tokyo, and resembling a mini field hospital, is providing medical services from a schoolyard in Ojiya, and close to 7,000 blankets, food, water, and kits of hygiene items and daily necessities have been distributed in an ongoing operation.