WASHINGTON » Several times every day, at airports across the country, passengers are trying to walk through security with loaded guns in their carry-on bags, purses or pockets, even in a boot. And, nearly a dozen years after 9/11, it’s happening a lot more often.

In the first six months of this year, Transportation Security Administration screeners found 894 guns on passengers or in their carry-on bags, a 30 percent increase over the same period last year. The TSA set a record in May for the most guns seized in one week — 65 in all, 45 of them loaded and 15 with bullets in the chamber and ready to be fired. That was 30 percent more than the previous record of 50 guns, set just two weeks earlier.

Last year TSA found 1,549 firearms on passengers attempting to go through screening, up 17 percent from the year before.

In response to a request from The Associated Press, the agency provided figures on the number of firearm incidents in 2011 and 2012 for all U.S. airports, as well as the number of passengers screened at each airport. The AP analyzed the data, as well as weekly blog reports from the agency on intercepted guns from this year and last year.

TSA didn’t keep statistics on guns intercepted before 2011, but officials have noticed an upward trend in recent years, said spokesman David Castelveter.

Some of the details make officials shake their heads.

As one passenger took off his jacket to go through screening in Sacramento, Calif., last year, TSA officers noticed he was wearing a shoulder holster, and in it was a loaded 9 mm pistol. The same passenger was found to have three more loaded pistols, 192 rounds of ammunition, two magazines and three knives.

Screeners elsewhere found a .45-caliber pistol and magazine hidden inside a cassette deck. Another .45-caliber pistol loaded with seven rounds, including a round in the chamber, was hidden under the lining of a carry-on bag in Charlotte, N.C. A passenger in Allentown, Pa., was carrying a pistol designed to look like a writing pen. At first the passenger said it was just a pen, but later acknowledged it was a gun, according to TSA.

A passenger in March at Bradley Hartford International Airport in Connecticut had a loaded .38-caliber pistol containing eight rounds strapped to his lower left leg. At Salt Lake City International Airport, a gun was found inside a passenger’s boot strapped to a prosthetic leg.

TSA doesn’t believe these gun-toting passengers are terrorists, but the agency can’t explain why so many passengers try to board planes with guns, either, Castelveter said. The most common excuse offered by passengers is "I forgot it was there."

"We don’t analyze the behavioral traits of people who carry weapons. We’re looking for terrorists," he said. "But sometimes you have to scratch your head and say, ‘Why?’"

Many passengers found to have guns by screeners are arrested, but not all. It depends on the gun laws where the airport is located. If the state or jurisdiction where the airport is located has tolerant gun laws, TSA screeners will frequently hand the gun back to the passenger and recommend locking it in a car or finding some other safe place for it. The government doesn’t track what happens to the people who are arrested.

Is it plausible that some people are so used to carrying guns that they simply forget that they have them, even when they’re at an airport about to walk through a scanner? Or do some people try to bring their guns with them when they fly because they think they won’t get caught?

Jimmy Taylor, a sociology professor at Ohio University-Zanesville and the author of several books on the nation’s gun culture, said some gun owners are so used to carrying concealed weapons that it’s no different to them than carrying keys or a wallet.

The most common reason people say they carry guns is for protection, so it also makes sense that most of the guns intercepted by TSA are loaded, Taylor said. Many gun owners keep their weapons loaded so they’re ready if needed, he said.

Even so, Taylor said he finds it hard to believe airline passengers forget they’re carrying guns.

"My wife and I check on things like eye drops and Chapstick to see if we’re allowed to take them on a plane, so it’s a little difficult to imagine that you aren’t checking the policies about your loaded firearm before you get to the airport," he said.

Occasionally passengers stopped by TSA are people who are used to carrying guns because they work in law enforcement, security or the military, but that doesn’t appear to be the case most of the time.

Robert Spitzer, an expert on gun policy and gun rights, theorizes that for some, the "I forgot" answer is an excuse, "just like somebody who walks out of a store with an unpaid-for item in their pocket. The first thing that person will say is, ‘I forgot.’ Do people forget sometimes? Sure they do. But are there also people who try to shoplift to get away with something? Sure there are, and I think that’s no less true with guns."

Eighty-five percent of the guns intercepted last year were loaded. The most common type of gun was a .38-caliber pistol.

Airports in the South and the West, where the American gun culture is strongest, had the greatest number of guns intercepted, according to TSA data.

Of the 12 airports with the most guns last year, five are in Texas: Dallas-Fort Worth International, 80 guns; George Bush Intercontinental in Houston, 52; Dallas Love Field, 37; William P. Hobby in Houston, 35, and Austin-Bergstrom International, 33. Hartsfield-Jackson in Atlanta had the most for any airport, at 96. Others include Phoenix Sky Harbor, 54; Fort Lauderdale-Hollywood International in Florida, 42; Denver International, 39; Seattle-Tacoma International, 37; Orlando International Airport in Florida, 36, and Tampa International in Florida, 33.

When expressed as a proportion of airport traffic volume, small airports in the West and South led the way. The airport in Roswell, N.M., had 8.5 guns intercepted per 100,000 passengers last year; Cedar City, Utah, and Provo, Utah, both 6.5; Longview, Texas, 4.9; Dickinson, N.D., 4; Joplin, Mo., 3.8; Twin Falls, Idaho, 3.4; Fort Smith, Ark., 3.3, and Walla Walla, Wash., and Elko, Nev., both 2.9.

By contrast, at John F. Kennedy International Airport in New York, where TSA screened nearly 27 million passengers last year, there was a single passenger found to have a gun.

"There are some Americans who believe that there are no limits, that they not only have a constitutional but a God-given right to have a gun and ‘By gosh, if I want to bring a gun on a plane I’m going to do it,’" said Spitzer, a professor at the State University of New York-Cortland.

TSA’s count of guns intercepted doesn’t include all the other kinds of prohibited "guns" that TSA screeners find, like flare guns, BB guns, air guns, spear guns, pellet guns and starter pistols. Screeners find half a dozen to several dozen stun guns on passengers or in their carry-on bags each week. Last December, screeners stopped a passenger in Boston with seven stun guns in his bag. He said they were Christmas presents. The same week, screeners spotted 26 stun guns in the carry-on bag of a passenger at JFK. TSA has found several stun guns disguised as smartphones, and one that looked like a package of cigarettes.

Passengers are allowed to take guns with them when they fly, but only as checked baggage. They are required to fill out a form declaring the weapons and to carry them in a hard-sided bag with a lock.

Most of those who are stopped with guns are reluctant to talk about it afterward. One who didn’t mind was Raymond Whitehead, 53, of Santa Fe, N.M., who was arrested at Newark Liberty International Airport in New Jersey in May after screeners spotted 10 hollow-point bullets in his carry-on bag. Whitehead, who is completely blind, also had a .38 caliber Charter Arms revolver in his checked bag that he had failed to declare. He said in an interview with the AP that he was unaware of the specifics of the rules for checking guns, or that hollow-point bullets are illegal in New Jersey.

Whitehead acknowledged that it seems "counterintuitive" for a blind man to have a gun but said he keeps a loaded gun handy for protection from intruders. In such a situation, he said, he would call out a warning that he had a gun and spray bullets in the direction of the noise if the intruder didn’t leave.

"I have five shots, and if I fan it out I’m going to hit you," said Whitehead, a National Rifle Association member who owns five guns.