Roland Buerk in Tokyo: "The fear is the pools of water could overflow spilling more radiation into the Pacific Ocean"
Operators of Japan's Fukushima nuclear plant have suspended an operation to clean contaminated water hours after it began due to a rapid rise in radiation.
Some 110,000 tonnes of water have built up during efforts to cool reactors hit by the 11 March earthquake and tsunami.The contaminated water, enough to fill 40 Olympic-sized swimming pools, has been at risk of spilling into the sea.
The disaster caused meltdown at three of the reactors, and radiation leaks.
It was the world's worst nuclear accident since Chernobyl in Ukraine in 1986.
The powerful earthquake and the tsunami it generated are now known to have killed more than 15,280 people, while nearly 8,500 remain unaccounted for.
Radioactive sludge? A spokesman for the plant operators, the Tokyo Electric Power Company (Tepco), said engineers were trying to find the cause of the jump in radiation levels.
"The level of radiation at a machine to absorb caesium has risen faster than our initial projections," the spokesman said.
