Federal officials said there would be heightened security for both domestic and international flights at airports across the country, but the intensified levels would likely be "layered," differing from location to location depending on alerts, security concerns and other factors.
Passengers can expect to see heightened screening, more bomb-sniffing dog and officer units and behavioral-detection specialists at some airports, but there will also be unspecified less visible precautions as well, officials said.
Passengers traveling to the U.S. from overseas will be restricted to one carry-on bag, statements from British Airways and Air Canada indicated.
According to a NBC report, international travelers will also be faced with:
•Pat-downs at security checkpoints involving the upper torso and legs.
•Inspections of all carry-on bags.
•A ban on blankets and pillows an hour before landing.
According to ENAC, Italy's aviation authority, the increased measures were requested by the U.S. Transportation Security Administration and will last for three days, NBC reports.
In a written statement, Department of Homeland Security Secretary Janet Napolitano said the additional measures "are designed to be unpredictable, so passengers should not expect to see the same thing everywhere."
Napolitano advised to allow extra time for check-in, but assured the public that they should "continue their planned holiday travel and, as always, be observant and aware of their surroundings and report any suspicious behavior or activity to law enforcement officials."
More Coverage from CBSNews.com:
Official: U.S. Knew of Suspect for 2 Years
U.S. Bolsters Security after Bomb Attack
Report: Father Warned of Bomb Suspect Son
Official: Explosive PETN Used in Attack
Jasper Schuringa ID'd as Flight 253 Hero
Failed Attack Signals New Threat?
Safety in the Air
Fight 253 Terror Scare
Obama Monitors 'Terror' Attempt