TOKYO (Reuters) - Scores of people fled Tokyo on Tuesday and residents stayed indoors over fears that radiation from an earthquake-stricken nuclear plant could waft over one of the world's biggest and most densely populated cities.
Despite assurances from the city government that low levels of radioactivity detected in Tokyo were for now "not a problem," residents, expatriates and tourists decided staying in Japan's capital was simply too risky.
Several companies evacuated staff. Visitors cut short vacations. Some airlines canceled flights and the U.S. Federal Aviation Administration said it was preparing to possibly reroute flights if the nuclear crisis worsened.
Those who remained in Tokyo hoarded food and supplies, fearing the worst from the radiation threat that spread panic in this bustling, ultra-modern and hyper-efficient metropolis of 12 million people.
At the city's main airports, hundreds of people lined up, many with children, boarding flights out.
"I'm not too worried about another earthquake. It's radiation that scares me," said Masashi Yoshida, cradling his 5-month-old daughter Hana at Haneda airport.
Tourists such as American Christy Niver, of Egan, Minnesota, said she'd had enough. Her 10-year-old daughter, Lucy, was more emphatic. "I'm scared. I'm so scared I would rather be in the eye of a tornado," she said. "I want to leave."
The stricken Fukushima nuclear power facility is 240 km (150 miles) north of Tokyo. Officials said radiation in the capital was 10 times normal by evening and was not harmful to health.
But confidence in the government is shaken, and many people prepared for the worst.
Don Quixote, a multistorey, 24-hour general store in the trendy Roppongi district, was sold out of radios, flashlights, candles, fuel cans and sleeping bags.
Many stores ran out of rice, a Japanese staple, while aisles that once stocked instant noodles and bread were emptied.
Around eight hours after fresh explosions rocked the plant, the U.N. weather agency said winds were dispersing radioactive material over the Pacific Ocean, away from Japan and other Asian countries. The Geneva-based World Meteorological Organization added that weather conditions could change.
Some scientists urged Tokyo residents to stay calm.
"Radioactive material will reach Tokyo but it is not harmful to human bodies because it will be dissipated by the time it gets to Tokyo," said Koji Yamazaki, professor at Hokkaido University graduate school of environmental science.
"If the wind gets stronger, it means the material flies faster but it will be even more dispersed in the air."
University of Tokyo bioengineering professor Hiroyuki Takahashi added: "If the nuclear fuel remains contained, there will be very little health risk."
These assurances offered little comfort for many.
Waiting at Narita airport, Gunta Brunner, a 25-year-old creative director from Argentina, said the risk of radiation exposure was more terrifying than another disaster.
"In an earthquake you can survive without many problems because in Tokyo everything is prepared. With the tsunami, if you are in the middle of Japan or in Tokyo it's not a problem. But with the radiation, you cannot escape and you can't see it."
About 350 Japan-based expatriates at Infosys Technologies Ltd, India's second-largest software services exporter, are returning to India, its chief executive, S. Gopalakrishnan, told Reuters.
U.S. banking giant Citigroup said it was keeping workers in Tokyo informed but there were no evacuation orders, said a spokesman, adding the bank was closely following guidance by the U.S. embassy, which has not urged nationals to leave.
Some international journalists covering the disaster from the worst-hit region around the northeastern city of Sendai were also pulling out.
The Tokyo office of Michael Page International, a British recruitment agency, was closing for the week. "I am leaving for Singapore tomorrow," said one employee.
The French embassy advised citizens to leave. The German embassy urged its nationals to consider doing the same, especially those with families.
Flights heading into Tokyo were nearly empty. "I am afraid to go back," said Makoto Usui, 74, about to board a flight from Hong Kong. "I don't know what to expect."
Additional reporting by Junko Fujita, Mayumi Negishi, Kei Okamura and Jon Herskovitz; Writing by Jason Szep; Editing by Miral Fahmy and Dean Yates