By Yoko Kubota and Kazunori Takada
TOKYO (Reuters) - Radiation injuries to three workers complicated the battle to control Japan's earthquake-damaged nuclear plant while fear of contamination from the world's worst nuclear crisis in 25 years grew both at home and abroad.
Engineers trying to stabilize the six-reactor nuclear power station in Fukushima, 240 km (150 miles) north of Tokyo, have pulled out of some areas of the plant pending safety checks two weeks after an earthquake and tsunami battered the plant.
About 27,400 people are dead or missing across northeast Japan after the March 11 disasters.
Explosions in three reactors at the Fukushima Daiichi power station last week made this the worst nuclear accident since Chernobyl in 1986 and raised fears of a catastrophic meltdown.
While that has not happened, radiation has been leaking and four of the plant's reactors are still volatile.
Engineers from the plant's operator, Tokyo Electric Power Co (TEPCO), have made some progress in restoring power needed to cool down overheating nuclear fuel.
But on Thursday, three workers replacing a cable were exposed to high levels of contamination by standing in radioactive water, officials said. Two were taken to hospital with what experts thought could be radiation burns.
A senior official at the country's nuclear safety agency said the accident would delay work.
"We are certainly at a crucial stage right now, so we should try to avoid delays as much as possible, but we also need to ensure that the people working there are safe," agency deputy director general Hidehiko Nishiyama told a news conference.
A TEPCO official said the engineers were working in a volatile environment and needed to be aware of the danger.
"We would like to let those on site know before we resume work," company official Akira Suzuki said on Friday.
The huge loss of life from the 9.0 magnitude earthquake on March 11 and the tsunami it triggered, together with the prospect of a nuclear nightmare, have brought Japan its darkest days since World War Two.
The crisis at the plant has raised apprehension about nuclear power, both in Japan and beyond, and the government of the world's third largest economy would have to review its nuclear power policy, the top government spokesman said.
"It is certain that public confidence in nuclear power plants has greatly changed," Chief Cabinet Secretary Yukio Edano told Reuters late on Thursday.
"In light of that, we must first end this situation and then study (it) from a zero base."
Japan's 55 nuclear reactors provide about 30 percent of its electric power. The percentage had been expected to rise to 50 percent by 2030, among the highest in the world.
Alarm has been spreading about leaking radiation.
Tokyo's 13 million residents were told on Wednesday not to give tap water to babies after contamination hit twice the safety level. But it dropped back to safe levels the next day.
Despite government appeals for people not to panic, many shops saw bottled water flying off the shelves.
"Customers ask us for water. But there's nothing we can do," said Masayoshi Kasahara, a clerk at a Tokyo supermarket. "We are asking for more deliveries, but we don't know when the next shipment will come."
Radiation above safety levels has also been found in milk and vegetables from Fukushima and the Kyodo news agency said radioactive cesium 1.8 times higher than the standard level was found in a leafy vegetable grown at a Tokyo research facility.
Singapore said on Thursday it had found radioactive contaminants in four samples of vegetables from Japan.
Earlier, Singapore and Australia joined the United States and Hong Kong in restricting food and milk imports from the zone, while Canada became the latest of many nations to tighten screening.
The estimated $300 billion damage from the quake and tsunami makes it the world's costliest natural disaster, dwarfing Japan's 1995 Kobe quake and Hurricane Katrina, which swept through New Orleans in 2005.
In Japan's north, more than a quarter of a million people are in shelters. Some elderly displaced people have died from cold and lack of medicines.
Exhausted rescuers are still sifting through the wreckage of towns and villages, retrieving bodies.
The official toll of dead and missing are both revised up every day. Police said on Thursday 9,811 people were confirmed dead and 17,541 were missing. Authorities have been burying unidentified bodies in mass graves.
Amid the suffering, though, there was a sense that Japan was turning the corner in its humanitarian crisis. Aid flowed to refugees, and phone, electricity, postal and bank services began returning to the north, sometimes by makeshift means.
"Things are getting much better," said 57-year-old Tsutomu Hirayama, staying with his family at an evacuation center in Ofunato town.
"For the first two or three days, we had only one rice ball and water for each meal. I thought, how long is this going to go on? Now we get lots of food, it's almost like luxury."
(Additional reporting by Linda Sieg, Sumio Ito, Mayumi Negishi, Shinichi Saoshiro and Kiyoshi Takenaka in Tokyo, Yoko Nishikawa, Jon Herskovitz and Chisa Fujioka in northeast Japan; Writing by Robert Birsel)