Ashcroft statement on 'dirty bomb' suspect

Full Story 8: It said the International Atomic Energy Agency, a division of the United Nations, has documented almost 400 cases of trafficking in nuclear or radiological materials since 1993.

While weapons-grade plutonium or uranium or freshly spent nuclear fuel would be the most deadly, they also would be the toughest to obtain, the Council on Foreign Relations said.

More accessible medical supplies used in cancer treatments and X-ray machines are thought to be less dangerous.