At least six so-called “credit card knives” have been confiscated at Jacksonville’s city hall in recent days.

Action News Jax crime and safety expert Ken Jefferson said the weapons, which are the size of credit cards and have sharp blades inside them, could pose a major threat if they are in the wrong hands.

“It’s a dangerous weapon; it’s a concealed knife folded into a little compartment that looks like a credit card,” Jefferson said.

The blade inside is metal, but it’s tucked into a plastic case.

Security officers know what to look for. The X-ray machine at City Hall can easily detect the weapon, and guards are on the lookout.

A number of the same knives were confiscated this week at Orlando International Airport.

The TSA said it finds the credit card knives on passengers nearly every day.

According to Jefferson, the smaller the weapons become, the more security companies will have to adapt.

“Simply because all of them are not metal, they don’t have a metal trim or anything, so you’re going to have to do a cursory search, simply a basic, simple courtesy pat-down,” Jefferson said.

Security officers said that for the most part, people forget they have the knives in their wallets. Regardless, the weapons will be confiscated at government buildings.