FILE PHOTO: Passengers scan their bags with Transportation Security Administration (TSA) employees at Terminal 4 of JFK airport in New York City, U.S., May 17, 2017. (Xinhua/REUTERS)

WASHINGTON, Feb. 7 (Xinhua) -- A record number of firearms were seized at U.S. airport checkpoints last year, showed data released Thursday by the Transportation Security Administration (TSA).

An average of 11.6 firearms were found in carry-on bags every day, for a total of 4,239 during all of 2018, roughly 86 percent of which were loaded, the TSA said in a release.

The guns were intercepted at 249 of the nation's 440 airports where TSA agents conducted the screening.

That marked an increase of more than 7 percent in firearm discoveries from 2017's total of 3,957, according to the TSA.

Atlanta's Hartsfield-Jackson International Airport topped the list of U.S. airports that led in terms of firearms seizures, followed by Dallas/Fort Worth, Phoenix, Denver, and Orlando, Florida.

In addition to guns, screeners found a host of other prohibited items in passenger carry-ons and checked baggage, including smoke grenades and replica mortar shells.

The TSA administrator, David Pekoske, has said the numbers reflect the fact that more Americans are carrying firearms, according to NBC News.

The discoveries also came during a year that saw airline travel up by 5.5 percent over 2017.

Firearm possession laws vary by state and locality. TSA may impose civil penalties of up to 13,333 U.S. dollars per violation, per person for prohibited items violations and violations of other TSA regulations.

The TSA is an affiliate of the U.S. Department of Homeland Security, with authority over the security of the traveling public in the United States. It was created as a response to the Sept. 11 attacks.