[cnn-photo-caption image= http://i2.cdn.turner.com/cnn/2009/images/01/09/art.inauguration.gi.jpg caption="No specific security threat has been detected thus far, according to an intelligence assessment."]WASHINGTON (CNN) - A U.S. intelligence assessment says the upcoming presidential inauguration offers an attractive target for terrorists, but it hastens to add no specific threat has been detected thus far.
Homeland Security Secretary Michael Chertoff told CNN Thursday, "I can assure you we will be looking up until the last minute to see if there is any indication of something."
A copy of the intelligence document was obtained by CNN and says in part that the inauguration is "a potential target for a terrorist attack" because many dignitaries will be attending it, it's a high profile and symbolic event and because of "the historic significance of the Nation's first minority President."
In an interview with CNN Homeland Security Correspondent Jeanne Meserve, Chertoff said "there is a vulnerability" during such a large event with incoming and outgoing presidents in attendance along with the Congress, and the Supreme Court.
According to Chertoff, the United States will be studying electronic intelligence, reviewing human intelligence received here and abroad and has numerous security measures in place to protect the participants and the public.
The intelligence assessment was prepared by the Department of Homeland Security, FBI and other agencies. It says there are "no credible reports indicating a threat" from either international or domestic terrorists.
The document says the swearing in of the first minority president "increases the potential threat, particularly stemming from individuals on the extremist fringe of the white supremacist movement." But it adds no such groups are known to have threatened the inauguration so far.
The threat posed by "lone offenders" not connected to organized groups is named in the assessment as the "greatest potential threat."
Such offenders are often the most difficult to detect. The document says there have been some reports of lone offenders making threats but no indication that any of the potential threats "have progressed past rhetoric to operational planning."