The UN atomic watchdog made clear on Tuesday it had seen no sign of any explosion
at one of Iran's
most sensitive nuclear plants, backing up Tehran's denial that such an incident had taken place last week.
The International Atomic Energy Agency (IAEA),
in an unusual move, made a brief statement following media reports at the weekend of significant damage at the underground Fordo
uranium enrichment site.
IAEA inspectors regularly visit Iranian nuclear sites, including the one at Fordo, and the UN agency suggested in its comment that they had been at the site after the reports in some Israeli and Western media of an explosion there.
"We understand that Iran has denied that there has been an incident at Fordo. This is consistent with our observations," IAEA spokeswoman Gill Tudor said in an emailed comment in response to a question.
In late 2011 the plant at began producing uranium enriched to 20 percent fissile purity, compared with the 3.5 percent level needed for nuclear energy plants.
The West says this takes Iran a significant step closer to producing weapons-grade material. Iran says its nuclear program is entirely peaceful.