A suspected al-Qaida plot to detonate a bomb during President Obama's inauguration was taken so seriously that Defense Secretary Robert Gates — a Bush administration holdover and the only member of Obama's Cabinet already confirmed by the U.S. Senate — was cloistered in an undisclosed, secure facility to preserve the line of succession in case an attack succeeded.

n the weeks leading up to the inauguration, officials worked around the clock to analyze intelligence reports that a group of Somali jihadists planned to infiltrate the United States from Canada to detonate explosives.

The president's national security advisers concluded the threat of a major terror attack during the inauguration was serious. One major concern: That a bomb detonated during the inauguration of an American president would do irreparable, "debilitating" damage to America's image abroad.

Although President Obama declined to be interviewed for the Times article, top presidential adviser David Axelrod told Baker the threat appeared to weigh heavily on the president-elect in the days leading up to the inauguration.

Officials now believe the intelligence reports were bogus, an effort by one Somali faction to dupe the United States into taking out a rival group. It indicates how difficult it can be to discern actual security threats from bogus ones.