Iran warns against US attack

Iran has expanded its uranium conversion facilities in Isfahan and reinforced its Natanz underground uranium enrichment plant, a U.S. think tank said, amid growing concern over possible U.S. military action. Talk of a U.S. attack has topped the international news agenda since a report in New Yorker magazine said this month that Washington was mulling the option of using tactical nuclear weapons to knock out Iran's subterranean nuclear sites. Former Iranian President Akbar Hashemi Rafsanjani said on Sunday that any U.S. attack on Iran over its nuclear programme would plunge the region into instability. U.N. Secretary-General Kofi Annan also warned that U.S. military intervention in Iran was not the best solution to resolve the nuclear standoff. The Institute for Science and International Security (ISIS) said in an email with commercial satellite photos attached sent to news media that Iran has built a new tunnel entrance at Isfahan, where uranium is processed into a feed material for enrichment. Just two entry points existed in February, it said. "This new entrance is indicative of a new underground facility or further expansion of the existing one," said ISIS, led by ex-U.N. arms inspector and nuclear expert David Albright. ISIS also released four satellite images taken between 2002 and January 2006 it said showed Natanz's two subterranean cascade halls being buried by successive layers of earth, apparent concrete slabs and more earth and other materials. The roofs of the halls now appear to be eight meters (26 feet) underground, ISIS said.