Japanese officials are now ordering 140,000 people living near nuclear power plants damaged by Friday's 9.0 earthquake and subsequent tsunami to stay indoors and seal their doors and windows.

Prime Minister Naoto Kan took to national TV to say that radiation has spread from four damaged nuclear reactors of the Fukushima Daiichi atomic power plant.

Japanese officials told the Vienna-based International Atomic Energy Agency (IAEA) that "radioactivity is being released directly into the atmosphere" after a fire broke out in a storage pond for spent fuel at one of the four reactors. The fire was extinguished earlier today.

IN PICTURES: Japan survivors

"Now we are talking about levels that can damage human health. These are readings taken near the area where we believe the releases are happening. Far away, the levels should be lower," said Yukio Edano, chief cabinet secretary.

"Please do not go outside. Please stay indoors. Please close windows and make your homes airtight. Don't turn on ventilators. Please hang your laundry indoors."

Until now, Japanese officials have said radiation levels at the plant were within safe limits.

And Tuesday foreign companies ordered evacuations of employees amid an upgrade about the severity of the nuclear disaster, according to Canada's CVT.ca news.

Japanese officials had originally rated the situation at the plant in Fukushima as a level 4 on the 7-point scale.

IN PICTURES: Japan survivors