Shops across Tokyo began rationing goods including milk, toilet paper, rice and water today as a run on bottled water coupled with delivery disruptions left shelves bare, nearly two weeks after the earthquake and tsunami.
Government spokesman Yukio Edano pleaded for calm, and officials urged residents to avoid panicked stockpiling, sending workers to distribute three small bottles of water each to an estimated 80,000 families with babies of 12 months or younger.
Anxiety over food and water remained high a day after Tokyo officials reported that the radioactive iodine in the city's tap water measured more than twice the level considered safe for babies.
New readings today showed the capital's tap water was back to safe levels, but the relief was tempered by elevated levels of the cancer-causing element in two neighbouring prefectures, Chiba and Saitama.
Radiation has been leaking from a nuclear plant 140 miles north east of Tokyo since it was struck by the March 11 quake and engulfed by the ensuing tsunami. Feverish efforts to get the plant's crucial cooling system operating have been beset by explosions, fire and radiation scares.
More than two dozen people have been injured trying to bring the Fukushima Dai-ichi plant under control.
The developments highlighted the challenges Japan faces as officials scramble to avert a major nuclear crisis after a magnitude-9 quake off Sendai triggered a tsunami that killed an estimated 18,000 people and left hundreds of thousands homeless.
Radiation has seeped into raw milk, sea water and 11 kinds of vegetables, including broccoli, cauliflower and turnips, grown in areas around the plant.
The US and Australia halted imports of Japanese dairy and produce from the region, Hong Kong said it would require that Japan perform safety checks on meat, eggs and seafood, and Canada said it would upgrade controls on imports of Japanese food products.
Concerns also spread to Europe. In Iceland, officials said they measured trace amounts of radioactive iodine in the air but assured residents it was "less than a millionth" of levels found in European countries in the wake of the 1986 Chernobyl disaster.