WASHINGTON - The Obama Administration will warn U.S. citizens to be vigilant as they travel in Europe, updated guidance prompted by al-Qaeda threats, American and European officials said Saturday.
The State Department will issue a "travel alert" for Europe today that advises Americans to stay vigilant on the continent because of threat information, U.S. officials said on condition of anonymity.
"This travel alert is a cumulative result of information we have received over an extended period," one administration official said. "We are constantly monitoring a range of threat streams and have monitored this and others for some time."
A European official briefed on the talks said the language in the U.S. alert is expected to be vague.
It won't address a specific country or specific landmarks, the official said.
European and U.S. officials have not identified any specific targets that terrorists might be considering, the official said.
Officials have called the threat credible but not specific.
Officials in Germany indicated they knew of information pointing to possible al-Qaeda attacks in Europe and the United States.
Intelligence sources said security agencies had disrupted plans by Pakistan-based militants for simultaneous strikes in London, as well as in major cities in France and Germany.
The plot involving al-Qaeda and allied militants was in the early stages and would have involved groups of assailants taking and killing hostages, possibly along the lines of the 2008 raid in Mumbai, India, in which 166 people died, the sources said.
Sweden announced Friday it had raised its threat alert to the highest level ever because of an increased threat of terror attacks.
Swedish security officials said the threat did not appear to be immediate and they did not cite any possible targets.
In Britain, the security level stood at "severe" - the second-highest in a five-step scale - and there were no plans to raise it further, according to a British security official.
Some U.S. allies in Europe expressed concern that the U.S. advice might include a warning for Americans to stay away from public places in Europe, saying that would be an overreaction to the threat information.
Some administration officials agreed and the White House adamantly denied such a blanket warning was being considered.
Intelligence officials believe Osama bin Laden is behind the terror plots to attack several European cities.
If true, this would be the most operational role that bin Laden has played in plotting attacks since Sept. 11, 2001.
Eight Germans and two British brothers are at the heart of an al-Qaeda-linked terror plot against European cities, but the plan is in its early stages, with the suspects calling acquaintances in Europe to plan logistics, a Pakistani intelligence official said Thursday.
One of the Britons died in a recent CIA missile strike, he said.
The Pakistani official said the suspects are hiding in North Waziristan, a Pakistani tribal region where militancy is rife and where the United States has focused many of its drone-fired missile strikes.
"We remain focused on al-Qaeda's interest in attacking us and attacking our allies," State Department spokesman P.J. Crowley said. "We will do everything possible to thwart them and will take steps as appropriate."
A travel "alert" is less serious than a full "travel warning," which could have big implications.
Hundreds of thousands of Americans are in Europe at any one time, including tourists, students, and businessmen.
While the government cannot stop people from traveling there or force them to return home, a formal travel warning could result in canceled airline and hotel bookings as well as deter non-U.S. travelers from going to Europe.
In addition, many U.S. college and university study-abroad programs will not send students to countries for which a warning is in place for insurance and liability reasons.
Under a "no double standard" rule, the government is obliged to share threat information that it has given diplomats and other officials with the general public.
The Pentagon declined to say whether it had increased security levels at any of its European bases.
"As a matter of policy we don't discuss specific force protection measures or levels," said Army Maj. Tanya Bradsher, a Defense Department spokesman.
The Italian Interior and Foreign Ministry, German Foreign Office, French Foreign Ministry, Interior Ministry, the national police, and the Paris police all declined comment.