Workers have returned to the Japanese Fukushima Daiichi nuclear plant after Tokyo Electric Power Company (TEPCO) briefly withdrew them from the site due to a rise in radiation levels.
About 50 employees had been working at the plant, attempting to stabilise the reactors where temperatures have shot up today, following three explosions and two fires.
Japanese Cabinet Secretary Yukio Edano told the BBC that radiation levels were now falling from 1,000 millisieverts on Wednesday morning to 600-800 millisieverts.
A fire broke out at reactor No 4 today, though flames can no longer be seen from the plant, according to Japan's nuclear safety agency.
The No 4 reactor had been closed for maintenance, however, its spent fuel rods are still stored on the site.
The Japanese plant was hit with the crisis following a 9.0 magnitude earthquake that in turn triggered a tsunami.