New York City and Washington, D.C., are on high alert after U.S. Intelligence officials announced Thursday evening that there is evidence of a possible terrorist attack planned for the 10th anniversary of the September 11 attacks.
In a statement Thursday, spokesman for the Department of Homeland Security Matt Chandler called the threat “specific, credible, but unconfirmed.” Officials believe that Al-Qaeda may be planning to detonate car bombs on bridges or tunnels in New York or Washington.
Although the details are vague, both cities are taking swift action to beef up security over the weekend.
In New York City, commuters can expect to see officers, bomb-sniffing dogs and bag checks at train stations and subways around the city, especially at larger stations such as Grand Central Terminal and Penn Station. Additionally, the police department will be canvassing the city, conducting sweeps of parking garages.
In Washington, city police will work 12-hour shifts and officials say that unattended cars parked near "critical infrastructure" will be towed.
Despite the lack of details, officials maintain that vigilance is necessary to keep everyone safe.
“We will undoubtedly get more reporting in the coming days. Sometimes this reporting is credible and warrants intense focus. Other times it lacks credibility and is highly unlikely to be reflective of real plots under way,” Chandler said.
 “We continue to ask the American people to remain vigilant as we head into the weekend.”

(Photo: Chris Hondros/Getty Images)