'Dirty-bomb' Threat Investigated
WASHINGTON — Despite deep skepticism about the credibility of captured al-Qaida leader Abu Zubaydah, the U.S. intelligence community is taking seriously his claim that his organization has the capability of building a radioactive "dirty bomb," a U.S. official said yesterday.
American intelligence agents have undertaken a widespread search for evidence to corroborate the statement made to U.S. interrogators in an undisclosed location where the Pakistani militant has been held since his arrest last month, the official said.
Believed to have been Osama bin Laden's chief of operations, Zubaydah claimed al-Qaida had given high priority to making such a bomb and using it against important targets in the United States.
Zubaydah had earlier warned that al-Qaida had targeted banks in the northeastern United States for terrorist attack, which prompted an FBI alert last week.
Al-Qaida's interest in dirty bombs has been well established, including through testimony at the 1998 trial of suspects in the bombings of U.S. embassies in Kenya and Tanzania. Though Zubaydah may be practicing psychological warfare, the threat has to be taken seriously because of the ease with which such a bomb can be constructed and detonated, the U.S. government official said.
Unlike the far more complicated and dangerous atomic bomb, which derives its enormous destructive power from an explosive nuclear chain reaction, a dirty bomb can be made by simply combining radioactive material with explosives.
"(It is) not very effective as a means of causing fatalities," Richard Meserve, chairman of the federal Nuclear Regulatory Commission, told a Senate Foreign Relations subcommittee last month. "But it could have a psycho-social effect, and terrorists' greatest weapon is fear."
Overseas, highly radioactive nuclear materials are scattered widely.
In 1995, Chechen rebels left an unexploded dirty bomb in a Moscow park to frighten Russians, noted John Parachini, an analyst at Rand Corp. The event received wide publicity, he said, though the radioactive level of the materials was so low that Russian authorities "laughed it off."