Rising radiation levels have forced the operator of Japan's stricken Fukushima nuclear power plant to suspend an operation to clean up radioactive water only hours after it began.
The operation got under way after being delayed by a series of glitches.
Now a spokesperson for Tokyo Electric Power Company, or TEPCO, says the level of radiation at a machine to absorb caesium has risen faster than initial projections.
Officials said earlier this week that large and growing pools of radioactive water at the Fukushima Daiichi plant were in danger of spilling into the sea within a week unless action was taken quickly.
TEPCO has pumped massive amounts of water into the plant to cool three reactors that went into meltdown when the earthquake and tsunami in March disabled cooling systems.
But managing the radioactive water has become a major headache as the plant runs out of places to keep it.
Around 110,000 tonnes of highly radioactive water is stored at the plant.