Bustling U.S. airports set a dubious record in 2017, intercepting nearly 4,000 firearms in passenger bags at checkpoints around the country, according to data released last week by the Transportation Security Administration.

Last year, the agency — which routinely confiscates questionable items that could be used as weapons — found a record 3,957 guns tucked away in carry-ons, according to the TSA's "Year in Review," which has tracked the figure since 2005. That tally represented a roughly 17 percent increase over the 2016 figure, averaging more than 75 firearms found per week. Of that number, 84 percent were loaded weapons.

In fact, during 2017 firearms were found at more than half of the 440 federalized airports around the U.S. The nation's busiest hub, Hartsfield-Jackson Atlanta International Airport, topped the TSA's list with 245; other offenders in the top 10 included both of Dallas' major airports, Houston, Denver, and Tampa and Orlando in Florida.

According to one expert, many of those cities share a common link.

"When you look at the top 10 airports with the highest seizures, a lot are in states where concealed carry is common," said aviation security expert Jeff Price. "In Atlanta, you can even carry a weapon in the public areas of the terminal building."