The top U.S. diplomat in Pakistan says the Obama administration does not know how many Americans might have disappeared overseas to train with al-Qaida or other terrorist groups.
The number is not thought to be large, but Ambassador to Pakistan Anne Patterson outlined a possible "nightmare scenario" — people holding U.S. passports receiving terrorist training then returning legally to the U.S. to commit violent acts.
She said in a speech Friday to the Pacific Council in Los Angeles that the U.S. is working with Pakistan and other governments to figure out how to identify such people.
She said after the speech "there are more out there than we know about."
Five American Muslims from the Washington, D.C., area were arrested last year in Pakistan, where they face possible terrorism charges.
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