KITAKAMI - Crews fighting to cool reactors at Japan's stricken nuclear plant managed to connect a power line as the government revealed that leaking radioactivity had reached the food chain.
The Fukushima No. 1 plant was crippled eight days ago by a terrifying earthquake and tsunami which according to the latest police tally left nearly 20,000 people dead or missing in Japan's worst natural disaster since 1923.
At least 7,653 people were confirmed killed - lost to the tsunami or buried in the wreckage of buildings. Sick and hungry survivors of the disaster are enduring desperate conditions and bitterly cold nights in the northeast.
The government of the world's third-biggest economy has been insisting that there is no widespread threat of radiation but confirmed Saturday that fresh foodstuffs were now showing signs of contamination.
Tainted milk was found in Fukushima prefecture, where the troubled plant is located, while contaminated spinach was discovered in neighbouring Ibaraki prefecture, chief government spokesman Yukio Edano told reporters.
The milk was found more than 30 kilometres from the plant, beyond a government exclusion zone.
But Edano urged consumers to remain calm, saying that even if a person were to drink the contaminated milk for a year, the radiation level would be the equivalent of one CT hospital scan.
"The government will do its utmost... to avoid health hazards and to resolve this problem," he said.
Abnormal levels of radioactive iodine were meanwhile found in the water supply in areas including Tokyo and Fukushima, officials said, stressing that also was not a risk to human health.
Unthreatening traces of radioactive caesium were also found in tap water in Tochigi and Gunma prefectures.
Engineers fighting to restore mains electricity at the overheating reactors connected a power line into the plant 250 kilometres northeast of Tokyo, and said they would continue pumping in seawater round the clock.
After an epic week-long tussle to control overheating at the facility, where the tsunami knocked out backup generators, the crews were expecting to restore electricity to four of its six reactors, officials said.
The nuclear safety agency said workers had connected a power line to reactor number two at the plant after the 9.0-magnitude earthquake - the biggest in Japan's recorded history - felled electricity pylons in the area.
"If no problem is found at the facility today, the power will resume as early as tomorrow (Sunday)," a spokesman for the agency said.
Once power is back up, radiation-suited engineers hope they can get the cooling systems online. In the meantime, they have been dumping water by hose and air on the reactors to avert a feared meltdown.
But given the extent of damage at the plant, it is unclear whether the cooling system would work even if power is restored.
The lack of power has sent the temperatures of fuel rods - both in the reactors and in separate containment pools - soaring as the coolant water that normally keeps them safely submerged has rapidly evaporated.
The threat of radiation seeping from the ageing plant carried a particular resonance for Ayako Ito, who at 84 is old enough to recall the World War II US atom bomb attacks on the cities of Hiroshima and Nagasaki.
"The most difficult part is that you can't see it but people can just disappear like that," she told AFP at her hillside home in Kamaishi, one of the northeast coastal towns that bore the full force of the towering tsunami.
"We're already not eating or drinking, and now this is happening to us? It's very difficult," she said.
Six workers at the nuclear plant have been exposed to high levels of radiation but are continuing working there and have suffered no health problems, the operator Tokyo Electric Power Co. said.
Half a million homeless people in Japan's northeast are struggling to stay warm with scant supplies of food and fuel after the March 11 tsunami reduced whole towns and villages to debris.
Yukiko Sakai, 33, said she had not seen her husband Kenji, whom she married on December 24, since the disaster.
On Saturday, for the second time, she visited a stadium that has been converted into a temporary morgue in Miyagi prefecture's Rifu city.
"If I don't find him here, that means he is still alive somewhere," she said, refusing to give up hope.
Well south at the Fukushima No. 1 atomic plant, crews were locked in what the UN nuclear watchdog said was a "race against time" to cool the reactors and prevent a major radiation leak after a series of explosions and fires.
Coming on top of the natural disaster, the nuclear emergency has stoked anxiety among governments and the public worldwide, with panic-buying of iodine pills in several countries, and contributed to turmoil on financial markets.
With Japan facing its biggest tragedy since World War II, reports said Prime Minister Naoto Kan had offered to form a national unity government to cope with the monumental disaster but had been rebuffed by the opposition.
Japan's nuclear agency has hiked the Fukushima accident level to five from four on an international scale measuring up to seven, an admission the crisis now at least equals the 1979 Three Mile Island accident in Pennsylvania.
The government has already evacuated an area 20 kilometres around the stricken plant and on Saturday began moving more than 800 patients from hospitals in a wider zone between 20 and 30 kilometres from the plant.
In the northeast disaster zone, a major international relief operation is under way for the homeless and millions left without water, electricity, fuel or enough food.
But thick snow has covered the wreckage littering obliterated towns and villages, all but extinguishing hopes of finding any trapped survivors.
"A lot of people have been having respiratory problems. We can monitor it, but we cannot do much more than that," said hospital surgeon Lee Yang-Sung, who is helping to treat patients evacuated to a spartan shelter in Kesennuma.
There was some relief from a slight rise in daytime temperatures, which melted the snow in some areas Saturday.
But the nights remain icy cold and the freezing weather is blamed for the deaths of a number of elderly, weakened survivors.