Airports nationwide are ramping up security following the botched attack of a Detroit bound airliner on Christmas day.

The Transportation Security Administration imposed a series of new rules on Saturday that will likely lengthen travel time for passengers.

So far, the government has been vague about the new security measures, saying that it wanted security screenings to be "unpredictable." Adding to the frustration, passengers will likely not find the same measures at every airport.

Meanwhile, some airlines have released detailed information on their newest restrictions, saying that passengers on international flights coming to the United States will apparently have to remain in their seats for the last hour of a flight, without any personal items on their laps.

That means passengers on flights of 90 minutes or less would most likely not be able to leave their seats at all, since airlines do not allow passengers to walk around the cabin before the plane reaches cruising altitude.

On its website, American Airlines said the T.S.A. had ordered that carry-on bags will undergo a second screening -- first at the security checkpoints and again at boarding.

Still, Homeland Security Secretary, Janet Napolitano, said passengers should proceed with their holiday plans and "as always, be observant and aware of their surroundings and report any suspicious behavior or activity to law enforcement officials."

The suspect in Friday's botched attempt, Umar Farouk Abdulmutallab, 23, tried to ignite a liquid explosive in the final hour of the flight while the plane was descending into Detroit.

Travelers are urged to leave extra time before boarding to undergo the newest security screenings.