|Injuries complicated work at the Fukushima nuclear plant [Al Jazeera]
The death toll from the huge earthquake and tsunami that devastated Japan's north-east coast has now topped 10,000, officials have announced.
At least 17,400 people are still missing, said the National Police Agency, two weeks after the disasters triggered further emergencies after damaging the cooling system at a nuclear power plant.
Work has now recommenced in parts of the stricken Fukushima plant which were evacuated after three workers were injured with suspected radiation burns on Thursday.
But a suspected reactor breach - a rupture in a crucial containment vessel for nuclear fuel - may set back any progress achieved in recent days.
"It seems that somehow the containment function could have been compromised somewhat, but we don't know more than that at the moment,' said Hidehiko Nishiyama, of the country's Nuclear and Industrial Safety Agency.
Officials later scaled back the likelihood of a reactor core breach.
A further two workers were taken on Friday morning to a specialist radiological institute after radiation-contaminated water seeped over the top of their protective boots, said the Associated Press news agency.
"The radiation level of the water which affected the injured is 10,000 times higher than the usual level," added Nishiyama.
It is understood that two of the reactors at the nuclear complex, 240km north of Tokyo, are now regarded as "safe" in what is termed a "cold shutdown". The other four reactors at the plant remain volatile, belching smoke and steam as work continues to cool fuel rods.
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The United States is shipping 2million litres of fresh water in a pair of barges to the plant. Workers had been pumping sea water into the reactors to lower temperatures and avert meltdowns, but there are concerns that, as the water boils off, salt is left behind - coating the mixed oxide fuel rods and preventing them from being efficiently cooled.
China's customs authorities told Reuters on Friday that two Japanese travellers entering China were found to have radiation levels "seriously exceeding limits". The pair were given medical treatment and presented no risk to others, said officials.
The report followed news of bottled water shortages after panic buying broke out in cities across Japan, as "higher than normal" levels of radiation were this week found in tap water near Tokyo.
But radiation levels have returned to normal, said officials, as Tokyo's governor drank a glass of water in front of cameras at a press conference outside a water purifying plant.
Singapore, Australia, The Philippines and Taiwan have joined the US and Hong Kong in restricting food and milk imports from the zone around the crippled nuclear power plant.
German shipping companies were reportedly avoiding the Tokyo Bay area ports due to radiation fears, as shipping industry officials said the country could face supply chain bottlenecks as vessels get diverted.
Yet ports in Tokyo, Yokohama, Kawasaki and Ichikawa are "very safe", said Japan's transport ministry on Friday. Transport officials added that all 15 ports damaged by the earthquake and tsunami are now operational for recovery and reconstruction efforts.
Naoto Kan, the Japanese prime minister, will today address the nation to mark the two week anniversary of the disasters.