Engineers have reconnected power cables to six Japanese nuclear reactors in the latest effort to fix the crippled and leaking Fukushima nuclear power plant.
However, Tokyo Electric Power Company officials warned that considerable work must be done before electric power can safely be turned on so the plant's cooling systems can fully operate again.
Smoke or steam was reported rising from at least one reactor on March 22, but workers continued efforts to cool reactors and spent-fuel ponds in order to avoid a large-scale release of radiation.
Graham Andrew, a high official with the UN's nuclear watchdog, the IAEA, said in Vienna that the situation at the plant remains dangerous.
"There continue to be some improvements at the Fukushima Daiichi nuclear power plant, but the overall situation remains very serious," Andrew said. "High levels of contamination have been measured in the locality of the plant."
Workers were forced to evacuate part of the plant on March 21 after smoke was seen coming out of reactor No. 3.
Japanese authorities say more than 8,900 people are dead after the March 11 earthquake and tsunami that crippled Fukushima Daiichi and devastated swaths of northeastern Japan. Another 12,600 people are still missing.
compiled from agency reports