Iran tunnel photos worry US officials

Washington: The sudden flurry of digging seen in recent satellite photos of a mountainside in central Iran might have passed for ordinary road tunnelling.

But the site is the backyard of Iran's most ambitious and controversial nuclear facility, leading US officials and independent experts to reach another conclusion: It appears to be the start of a major tunnel complex inside the mountain.

The question is, why? Worries have been stoked by the presence nearby of fortified buildings where uranium is being processed.

Those structures in turn are now being connected by roads to Iran's nuclear site at Natanz, where the country recently started production of enriched uranium in defiance of international protests.

As a result, photos of the site are being studied by governments, intelligence agencies and nuclear experts, all asking the same question: Is Iran attempting to thwart future military strikes against its nuclear programme by placing key parts of it in underground bunkers?

The construction has rai-sed concerns at the International Atomic Energy Agency. On Friday, an IAEA spokeswoman confirmed the agency has broached the subject with Iranian officials.

"The tunnel complex certainly appears to be related to Natanz," said David Albright, a former UN arms inspector and president of the Institute for Science and International Security, a Washington-based group that provided copies of the photos to The Washington Post. "We think it is probably for storage of nuclear items.''

Averting aerial strikes

A tunnel complex would reduce options for a pre-emptive military strike to knock out Iran's nuclear programme, according to US officials who closely follow Iran's nuclear activities.

It also could further heighten tensions between the Bush administration and Tehran.

In a report analysing the photos, officials of the Institute for Science and International Security, or ISIS, compared the new Natanz construction with a tunnel built by Iran inside a mountain near another key nuclear site.

That site, located about 80 miles to the south at Isfahan, is home to a major nuclear research centre and a factory that converts uranium to a form that can be enriched at Natanz.