Americans warned to be vigilant in Europe after terror threat

US warned Americans traveling in Europe to be vigilant following weeks of discussion within the Obama administration about threats of an attack by an al-Qaeda-affiliated terrorist group, officials said.

"Terrorists may elect to use a variety of means and weapons and target both official and private interests," the US State Department said in a travel alert for Europe issued in Washington yesterday.

According to Bloomberg.com, the State Department didn't issue a higher level "Travel Warning" for the continent. A warning would have cautioned Americans to avoid Europe, their most popular foreign travel destination, with the potential for a much larger impact on airlines and hotels.

Twelve million Americans traveled to Europe last year, spending more than $20 billion, according to Commerce Department data.

"There may be a little dip in bookings, especially on the leisure side," Kevin Mitchell, chairman of the Business Travel Coalition in Radnor, Pennsylvania, said in an interview after the alert was issued. "All bets are off if the threat is more specific or, God forbid, something happens."

The State Department has been monitoring the threats in Europe for weeks and made the decision to issue the advisory this weekend based on the "cumulative effect of all types of information" it had, Undersecretary of State Patrick Kennedy told reporters.