WASHINGTON -- U.S. law enforcement authorities believe as many as three dozen Americans who converted to Islam in prison have traveled to Yemen, possibly to train with Al Qaeda, according to a Senate report.
The "radicalization" of the individuals has alarmed U.S. officials even though no evidence has tied them to terror activities.
Several of the individuals have "dropped off the radar" for weeks at a time and continue to carry U.S. passports, according to a copy of the report obtained by The Associated Press.
"Al Qaeda's recruitment tactics also have changed," Kerry wrote in an introduction to the report. "The group seeks to recruit American citizens to carry out terrorist attacks in the United States."
Al Qaeda forces in Yemen have emerged in recent months as a pressing threat to U.S. security, with ties to a recent airline bombing plot and the shooting deaths of 13 people at the U.S. Army's Fort Hood post.
The White House and Pentagon have said they have no plans to send ground troops there, and Yemen has made clear it would not want them. Remaining options would include covert strikes against Al Qaeda targets and increased aid to help train and equip Yemen's own security forces.
Gen. David Petraeus, head of U.S. Central Command whose command territory includes Yemen, has said he would like to double military aid to that country, which currently is receiving about $67 million.
Kerry's report was expected to set the stage for a Wednesday public hearing on Yemen with testimony from senior State Department officials.
In addition to its finding that Al Qaeda was trying actively to attract "nontraditional followers" who could penetrate U.S. security, the staff report concludes that Al Qaeda has remained a viable threat.
"Despite setbacks, Al Qaeda is not on the run," the report concludes.
Kerry's staff also cites as many as 10 non-Yemeni Americans, in addition to the nearly three dozen prisoners, who moved to Yemen, became Islamic fundamentalists and married Yemeni women to remain in the country.
"Described by one American official as 'blond-haired, blue eyed-types,' these individuals fit a profile of Americans whom Al Qaeda has sought to recruit over the past several years," the report states.