Worldwide Caution
May 29, 2001
The U.S. Government learned in early May 2001 that American citizens abroad may be the target of a terrorist threat from extremist groups with links to Usama Bin Ladin's Al-Qaida organization. In the past, such individuals have not distinguished between official and civilian targets. As always, we take this information seriously. U.S. Government facilities worldwide remain at a heightened state of alert.
http://travel.state.gov/wwc1.html