The United Nations says it is worried that it is not getting complete information from Japan about its quake-stricken nuclear plant at Fukushima.
A senior official at the UN's International Atomic Energy Agency (IAEA) said it had not received full data for some time on the situation at reactor 1 at the Fukushima Daiichi plant.
It lacked information on temperatures of the spent fuel pools of reactors 1, 3 and 4, though Japan was supplying other updates, the official said.
The plant was badly damaged after a 9.0-magnitude earthquake triggered a tsunami that devastated the northeast coast of Japan on 11 March.
Workers at the No 2 reactor temporarily halted work on Wednesday after radiation levels went into the danger zone.
Engineers have been battling to cool the reactors and spent fuel ponds to avoid a large-scale release of radiation. Power cables have now been attached to all six reactors in the hope of restarting the cooling systems.
Workers have also restored lighting to the control room at the No 3 reactor, making it easier for engineers working to restore full power to the plant.
The IAEA says the overall situation at the facility remains very serious and the source of radiation still being emitted has not been identified. The Pentagon says it is monitoring that radiation.
The US military has declared an 80km no-go zone around the plant and last week announced a voluntary evacuation of families of troops stationed on Japan's main island of Honshu.
6.0 quake jolts northern Japan
An earthquake with a preliminary magnitude of 6.0 jolted parts of northern Japan near a quake-stricken nuclear power plant on Wednesday, national broadcaster NHK said.
There were no immediate reports of damage. Numerous aftershocks have been rocking the country following the quake and tsunami.
