Tourists mix with Spaniards in Madrid, Spain, Sunday Oct. 3, 2010. The State Department plans to caution Americans traveling in Europe to be vigilant because of heightened concerns about a potential ... more 
Tourists mix with Spaniards in Madrid, Spain, Sunday Oct. 3, 2010. The State Department plans to caution Americans traveling in Europe to be vigilant because of heightened concerns about a potential al-Qaida terrorist attack aimed at U.S. citizens and Europeans. The travel alert expected to come out Sunday is for travelers' guidance, is general in nature and isn't intended to focus on any specific country, location or tourist sites, senior U.S. officials told The Associated Press. less 
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Associated Press | Photo By Paul White
Tue, Oct 5, 2010 8:56 AM EDT