White smoke rising on Tuesday from reactor No. 2 at Japan's stricken nuclear power plant is likely to be steam from the spent nuclear fuel pool, Japan's nuclear safety agency said.
Earlier on Tuesday, steam appeared to rise from reactor No. 2 and white haze was detected above reactor No. 3.
There have been several blasts of steam from the reactors during the crisis triggered by a huge earthquake and tsunami on March 11 that left at least 21,000 people dead or missing.
Experts say the blasts probably released a small amount of radioactive particles.