Iran produced and experimented with polonium, a radioactive element that can be used in the chain reaction that produces a nuclear explosion, diplomats who have seen a status report on Iran's nuclear activity told CNN.
WASHINGTON, Feb 24 (Reuters) - CIA Director George Tenet said on Tuesday despite strides made against the al Qaeda network it remained capable of conducting an attack on the scale of Sept. 11, 2001.
"Even catastrophic attacks on the scale of 11 September remain within al Qaeda's reach," he said in a testimony to the Senate Intelligence Committee. "Make no mistake, these plots are hatched abroad, but they target U.S. soil or that of our allies."
Tenet said al Qaeda leader Osama bin Laden "has gone deep underground. We are hunting him in some of the most unfriendly regions on earth. We follow every lead."
He praised Pakistani President Pervez Musharraf for helping in the war against terrorism, calling him "a courageous and indispensable ally who has become the target of assassins for the help he's given us."
Tenet was presenting an assessment of the worldwide threat to security and was expected to come under criticism for the quality of intelligence on Iraq before last year's U.S.-led invasion. The CIA said President Saddam Hussein had threatening weapons of mass destruction but none have been found.
Tenet said in his testimony that one of the dangers that must be overcome is a global anti-American movement infected by bin Laden's agenda.
He said a steady growth of anti-U.S. sentiment among Sunni arab extremists "and the broad dissemination of al Qaeda's destructive expertise, ensure that a serious threat will remain for the foreseeable future -- with or without Al Qaeda in the picture."
Referring to plots using aircraft, he said authorities had uncovered new plans to recruit pilots and to evade new security measures in Southeast Asia, the Middle East and Europe.
Al Qaeda was blamed for the Sept. 11, 2001, attacks using hijacked planes in America that killed about 3,000 people.
Bin Laden is believed to be hiding in the mountainous border region of Afghanistan and Pakistan.