Tokyo water deemed unfit for babies as radiation detected (UPDATES) (VIDEO)

TOKYO, Japan — Tap water in Tokyo is now unfit for babies to drink due to increased levels of radiation, officials said Wednesday as the United States halted imports of some foodstuffs from the zone around Japan's troubled nuclear plant amid fears of contamination.

Tests found radioactive iodine levels double the level considered safe for infants at a water purification plant supplying Tokyo and other cities, officials said. Tokyo's governor Shintara Ishihara said there was no immediate health threat and urged people to "remain calm."

The decision by the Food and Drug Administration (FDA) to halt halt the import of milk, vegetables and fruits makes the United States the first country to block produce from Japan after a 9.0 earthquake and tsunami devastated much of the country on March 11 and set off a nuclear accident, Reuters reports.

Imports will be halted from four prefectures in Japan's northeast, which was hit hardest by the disaster.

It states that some private importers have already stopped shipments.

The FDA said the banned foods will be detained at the entry and not sold to the public, AP reports. Other foods from Japan such as seafood will continue to be sold but will be screened for radiation.

Japanese officials said Wednesday that in addition to milk and water, 11 types of vegetables from the tsunami-hit area had shown above-safety radiation levels.

They also insisted there was no danger to humans.

Japan's Fukushima Daiichi nuclear power plant has been leaking radiation since the tsunami, which damaged its cooling systems.

On Wednesday, black smoke rose from the heavily damaged No. 3 reactor, leading Tokyo Electric Power Co. to evacuate workers from the plant. The company said it was unclear what caused the smoke.

On Tuesday, a pool containing spent fuel rods at the plant had almost boiled over, sending fresh tremors of fear among workers battling to cool it down.

The water began to simmer in the No. 2 reactor, one of two reactors that had to be shut down Monday after emitting smoke and steam. Workers returned to the scene, rotating in and out of the most critical area for carefully limited periods to avoid exposure to radiation through their protective gear.

Technicians have been able to perform on-again, off-again work on the stricken plant. Already the double-whammy disaster has claimed a confirmed 9,080 lives, according to the national police, and another 13,561 are still missing.

The water in the overheating pool on Tuesday reportedly cooled down enough for fire trucks to pour more seawater onto the reactors later in the day, but government officials did not seem to have a firm grasp on events.

“We are taking necessary measures” to create “a stable situation at a low temperature level,” said Hidehiko Nishiyama, deputy director of the nuclear safety agency. “We must take care of it as quickly as possible.”

The lack of electricity at the plant prevents officials from knowing exactly what is going on inside, Nishiyama said. “When we restore the supply of electricity, we will know for sure the actual situation and ensure measures are adequate to insure a sustainable cooling system,” he said.

Despite reports that power cables had been reconnected to all six of the affected reactors, the difficulties in reducing the temperature of the cooling pools made it impossible to shut down all the reactors.

Nonetheless, Nishiyama said a total nuclear meltdown was out of the question. “We do not,” he said, “anticipate the possibility of a meltdown.” Although the cores of three of the reactors have been damaged, officials believed they had contained the damage.

Watch this video on how the food scare is impacting shopping choices in Tokyo.