The Science and Technology Agency informed the International Atomic Energy Agency early Thursday that the exterior of the roof of the uranium-processing plant where Japan's worst nuclear accident occurred last week is not damaged, agency officials said.

In its report to the atomic organization, which had asked for details of the extent of the damage, the agency attached a photograph of the accident site taken after the disaster, they said.

The move came in response to IAEA requests for formal confirmation that the building was not badly damaged after foreign media reports said that there had been "an explosion" at the plant, the officials said.