IAEA Report: 'Serious' Concerns on Iran Nuclear Activities

The U.N. atomic agency has "serious concerns" about Iran's nuclear activities, and has "credible" information Tehran may have worked on developing nuclear weapons, a report seen by Agence France Presse said Tuesday.

"The agency has serious concerns regarding possible military dimensions to Iran's nuclear program," the keenly awaited International Atomic Energy Agency report said.

"After assessing carefully and critically the extensive information available to it, the agency finds the information to be, overall, credible.

"This information indicates that Iran has carried out activities relevant to the development of a nuclear explosive device."

It added: "The information also indicates that prior to the end of 2003, these activities took place under a structured program, and that some activities may still be ongoing.

"Given the concerns identified above, Iran is requested to engage substantively with the agency without delay for the purpose of providing clarifications."

The Vienna-based agency said some of its more than 1,000 pages of information indicated Iran has done work "on the development of an indigenous design of a nuclear weapon including the testing of components."

Previous IAEA assessments have centered on Iran's efforts to produce fissile material -- uranium and plutonium -- which can be put to peaceful uses like power generation, or be used to make a nuclear bomb.

But the new update focuses on Iran's alleged efforts towards putting the radioactive material in a warhead and developing missiles.

It comes amid rising speculation that Israel might launch a pre-emptive military strike in an attempt to knock out its arch foe's nuclear facilities.

Iran, which says its nuclear program is peaceful and which has been hit by four rounds of UN Security Council sanctions, dismissed the new IAEA report prior to its publication, saying it was based on falsified information.

Russia and China had meanwhile pressured the IAEA not to even publish the report, diplomats said, and as a result it is unclear what action the agency's board will take when it meets next week.

Russian President Dmitry Medvedev warned Tuesday that Israeli threats to attack Iran over its nuclear program were "extremely dangerous rhetoric" that could result in a "catastrophe".