TSA screeners found a record number of firearms in airline passenger carry-on bags last year, according to data released Thursday by the agency.
An average of nearly 12 weapons were found every day, for a total of 4,239 during all of 2018.
The discoveries came during a year that saw airline travel up by 5.5 percent over 2017. TSA said "significant security enhancements" also contributed to the record number of guns found.
Read more from NBC News:
New Trump rules make it easier for U.S. gun makers to sell overseas
Ungodly abuse: The lasting torment of the New Tribes missionary kids
Arizona city officials want border wall's razor wire removed
Nearly nine out of every 10 of the weapons found were loaded, the TSA said, and of those a third had a round chambered. The guns were found at 249 of the nation's 440 airports where TSA conducts the screening.
The airports with the largest number of firearms seizures were in the South and the West. Atlanta's Hartsfield-Jackson led the list, followed by Dallas/Fort Worth, Phoenix, Denver, and Orlando, Florida. Four of the top 10 were in Texas: George W. Bush Intercontinental in Houston, Austin-Bergstrom, Dallas/Fort Worth and Dallas Love Field.
In addition to guns, screeners found a host of other prohibited items in passenger carry-ons and checked baggage. Three smoke grenades were found at Nashville International Airport, and the discovery of five replica mortar shells at Orlando's airport caused authorities to shut down screening operations until an explosive specialist arrived and declared the items safe.
The number of weapons found has gone up every year since TSA began reporting the data — from 926 in 2008 to 4,239 last year. And the rate of guns seized per passenger screened has also risen steadily.
The TSA administrator, David Pekoske, has said the numbers reflect the fact that more Americans are carrying firearms.