Fresh Concerns About Iran's Nuclear Programme

The UN nuclear agency says Iran has increased production of higher-grade enriched uranium, raising fresh concerns about how quickly it could make an atomic bomb.

A report by the International Atomic Energy Agency (IAEA) said Iran had failed to give a convincing explanation about a quantity of missing uranium metal.

Diplomats have said it could be used for experiments to arm a warhead.

Iran insists it has no intention of making nuclear weapons and maintains the sole purpose of its activities is to generate energy.

The report follows the recent abortive visit to Iran by IAEA inspectors.

It said: "An intensive discussion was held on the structured approach to the clarification of all outstanding issues related to Iran's nuclear programme.

"No agreement was reached between Iran and the Agency, as major differences existed with respect to this approach."

The report added: "The agency continues to have serious concerns regarding possible military dimensions to Iran's nuclear programme."

The report said Iran has tripled production of 20% enriched uranium since its last assessment in November, with 696 centrifuges installed at its heavily-guarded Fordo site - although all are of the older variety.

Uranium further enriched to 90% purity could in theory be used in a nuclear bomb.

A senior official familiar with the investigation said during their two visits to Tehran in the past month - another is not planned - the IAEA teams spoke only to "middle men."

"Iran wanted to constrain the process, and put us in a harness," the official said on condition of anonymity.

In particular, the IAEA said there was a "disappointing" refusal by Iran to allow the team access to the Parchin military site near Tehran, where an IAEA report in November said scientists had conducted suspicious explosives tests.

That report focused on a number of areas where the IAEA believes Iran carried out activities that could be be aimed at developing nuclear weapons.

Iranian officials repeated their assertion during the recent visits that the November report, which has prompted Western countries to ramp up sanctions, was based on forgeries, the official said.

Concerns raised by the IAEA has heightened speculation that Israel may launch air strikes in an attempt to knock out Iran's nuclear facilities, possibly even later this year.

In a separate development, Russian Prime Minister Vladimir Putin said he believes some western nations are using fears about Iran's nuclear programme as a pretext "to change the regime".

"I think that under the appearance of a struggle to prevent the proliferation of nuclear weapons... attempts of a different kind are being made and other aims are being set," he said.