At the source of the anxiety — the overheated, radiation-leaking nuclear plant — there was yet another setback Thursday as two workers were injured when they stepped into radiation-contaminated water. The two were treated at a hospital.

Supplies of bottled water grew scarce in Tokyo, one day after city officials warned that the level of radioactive iodine in the tap water was more than twice what is considered safe for babies to drink. Tests conducted Thursday showed the levels in the city’s water fell to acceptable limits for infants, but they were up in neighboring regions.

Frightened Tokyo residents hoping to stock up on bottled water and other goods flocked to shops across the city, some of which tried to prevent hoarding by imposing buying limits.

"The first thought was that I need to buy bottles of water," said Reiko Matsumoto, a real estate agent and mother of a 5-year-old, who rushed to a nearby store to stock up on supplies. "I also don’t know whether I can let her take a bath."

The shortages were mainly limited to basic staples, such as rice, instant noodles and milk. Vegetables, meat and tofu, meanwhile, were readily available in most places.

Japan has been grappling with an avalanche of miseries that began with a massive, 9.0-magnitude earthquake on March 11. That triggered a violent tsunami, which ravaged the northeast coast, killed an estimated 18,000 people and left hundreds of thousands homeless. The quake and tsunami also damaged the critical cooling system at the Fukushima Dai-ichi plant, which overheated and began spewing radiation into the environment.

Workers have been struggling to get the cooling system operating again, but their efforts have been hampered by explosions, fires and radiation scares. Lighting was restored Thursday to the central control room at Unit 1 for the first time since the quake and tsunami.

But two workers were hospitalized after stepping into contaminated water while laying electrical cables in one unit, nuclear and government officials said. The water seeped over the top of their boots and onto their legs, said Takashi Kurita, spokesman for plant owner Tokyo Electric Power Co.

The two likely suffered "beta ray burns," Tokyo Electric said, citing doctors. They tested at radiation levels between 170 to 180 millisieverts, well below the maximum 250 millisieverts allowed for workers, said Fumio Matsuda, a spokesman for the Nuclear and Industrial Safety Agency.

The men will be transferred to a radiology medical institute Friday, said Hidehiko Nishiyama, another nuclear agency spokesman. Their injuries were not life-threatening.

More than two dozen people have been injured trying to bring the plant, located 140 miles northeast of Tokyo, under control.

The death toll from the earthquake and tsunami continued to rise, meanwhile, with more than 9,800 bodies counted and more than 17,500 people listed as missing. Those tallies may overlap, but police from one of the hardest-hit prefectures, Miyagi, estimate that the deaths will top 15,000 in that region alone.

The crisis has stoked fears about the safety of Japan’s food and water supply. Radiation has been found in raw milk, seawater and 11 kinds of vegetables, including broccoli, cauliflower and turnips, grown in areas around the plant.

The U.S. 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. Singapore, too, has banned the sale of milk, produce, meat and seafood from areas near the plant.

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 Europe in the wake of the 1986 Chernobyl disaster — the world’s worst nuclear accident.

Radioactive iodine is short-lived, with a half-life of eight days — the length of time it takes for half of it to break down harmlessly. However, experts say infants are particularly vulnerable to radioactive iodine, which can cause thyroid cancer.

In Tokyo, government spokesman Yukio Edano pleaded for calm over the water contamination, and said the government was considering importing bottled water from other countries to cover any shortages. Officials urged residents to avoid panicked stockpiling and the city began distributing 240,000 bottles — enough to give each of the 80,000 children under age 1 three small bottles of water.

New readings Thursday showed the city’s tap water was back to levels acceptable for infants, but the relief was tempered by elevated levels of the isotope in two neighboring prefectures: Chiba and Saitama. A city in a third prefecture, just south of the plant, also showed high levels of radioactive iodine in tap water, officials said.

Tap water in Kawaguchi City in Saitama, north of Tokyo, contained 210 becquerels of radioactive iodine — well above the 100 becquerels considered safe for babies but below the 300-becquerel level for adults, Health Ministry official Shogo Misawa said.

In Chiba prefecture, the water tested high for radiation in two separate areas, said water safety official Kyoji Narita. The government there warned families in 11 cities in Chiba not to give infants tap water.

"The high level of iodine was due to the nuclear disaster," Narita said. "There is no question about it."

Radiation levels also tested dangerously high in Hitachi in Ibaraki prefecture, about 70 miles south of the Fukushima plant, city water official Toshifumi Suzuki said, adding that officials were distributing bottled water.

The limits refer to sustained consumption rates, and officials said parents should stop using tap water for baby formula, although it was OK for infants to consume small amounts.

Despite the appeals, shelves were bare in many stores across Tokyo.

Maruetsu supermarket in the city center sought to impose buying limits on specific items to prevent hoarding: only one carton of milk per family, one 11-pound bag of rice, one package of toilet paper, one pack of diapers. Similar notices at some drugs stores told women they could only purchase two feminine hygiene items at a time.

Maruetsu spokeswoman Kayoko Kano acknowledged that the earthquake and tsunami resulted in delays of some products.

Some frustrated shoppers have turned to the city’s many vending machines as an alternative. The machines are found everywhere in the city and one can feature about three dozen different beverages — ranging from hot coffee and green tea to power drinks and juice. A 500-milliliter bottle of imported water costs about $1.25.

A spokesman for Procter & Gamble Japan said its plant was fully operational but that rolling blackouts in Tokyo may be affecting distribution. "Consumers are nervous, and they may be buying up supplies," Noriyuki Endo added.

Worse hardships continued in the frigid, tsunami-struck northeast. Some 660,000 households still do not have water, the government said. Electricity has not been restored to some 209,000 homes, Tohoku Electric Power Co. said. Damage is estimated at $309 billion, making it the most costly natural disaster on record.

In one bright spot of economic news, Toyota Motor Corp. — which had suspended production due to damage to suppliers’ factories and power shortages in the quake zone — said it will soon resume production of the Prius and two other hybrid models.

But rival Honda Motor Co. said the suspension of car production at its Saitama and Suzuka factories will be extended to April 3.

The economic woes spawned by the disasters were especially painful for farmers in the region near the nuclear plant.

Sumiko Matsuno, a 65-year-old farmer in Fukushima, spent Thursday frantically harvesting vegetables from her fields.

"We are digging up all our carrots and onions as fast as we can. We can’t sell them but we need them ourselves for food," she said. "We are really worried about our future. If this goes on, it is going to really hurt us."

___

Associated Press writers Eric Talmadge in Fukushima, and Mari Yamaguchi, Elaine Kurtenbach, Yuri Kageyama, Kaori Hitomi, Jean H. Lee and Ian Mader in Tokyo contributed to this report.