Security tighteded at US airports

In the wake of the latest attempted plane attack, two things are assured for American travelers during the holiday season -- long lines and heightened security checks.

The US Department of Homeland Security is advising passengers that they may experience increased scrutiny.

A wide range of security measures will be implemented when needed, from bomb sniffing dogs to behavior detection to other techniques, both seen and unseen. Customers at Dulles International Airport, near Washington DC, had mixed feelings about flying on Saturday.

Mary Riverra, Passenger, said, "Anytime you fly, it's a little nerve wracking, and to have something like that happen the day before you're flying ... a little scary. We're trying not to think about it. Think positive that we'll be on a good flight, and nothing will happen."

Dee O'connor, Passenger, said, "I think it's probably the safest day to fly because everyone's going to be on very high alert, and make sure they are doing their job as well as they can."

Cpl. Frederick of the Wayne County Airport Police and his bomb- sniffing dog Spencer patrol at the Detroit Metropolitan Airport. (AFP/Getty Images/Bill Pugliano)