LaGuardia Airport and airports around the country were put on high alert Wednesday.

Although no specific threat exists, the Transportation Security Administration, which operates under the federal Department of Homeland Security, warned airports that terrorists may be exercising "dry runs" to see what objects can be snuck through security checkpoints.

TSA officials said that during the past year, four different airports seized regular items that seemed suspicious. Among those were wires, switches, tubes, cell phones and blocks of cheese. Terrorism analyst Harvey Kushner said a block of cheese is of similar weight, size and texture to plastic explosives.

As for travelers' reactions, it's a mixed bag. Some expressed dissatisfaction with the extra security, calling it inconvenient. Others said they're alright with it as long as they get to their destination safely.