SALT LAKE CITY (AP) -- Four guns. A set of Samuri swords. A 2-foot-long artillery shell. Authorities seized or detected those weapons in the past week alone from the luggage of passengers at the Salt Lake City International Airport — a haul that one top official called a spike in weapons, although none of the owners was suspected of intending to do harm.
One of the guns belonged to a prominent Utah businessman, Overstock.com CEO Patrick Byrne, who was arrested for carrying a gun inside an airport terminal. He spent nearly three hours overnight Wednesday in a holding cell at the Salt Lake County jail.
Byrne told authorities he didn't realize the .40-caliber Glock was inside his carry-on bag. The pistol had a magazine with a dozen bullets, but none loaded in the chamber, the Transportation Security Administration said.
Another Salt Lake passenger was found packing two Samuri swords on Jan. 10 at a security checkpoint. The owner was allowed to return to an airline counter, check the swords and continue on his flight.
It wasn't the most unusual item federal agents flagged recently at Salt Lake's airport.
That was a polished 105-mm artillery shell, discovered Monday inside a passenger's checked bag.
Artillery shells are not permitted in carry-on or checked bags, Vera Adams, the federal security director for Utah, said Friday.
The casing was empty of explosive material, like an empty bullet. But the shell still had a live primer that presented a fire risk, said Mark Lewis, Utah's deputy federal security director and a former Marine.
"This is really more of a haz-mat issue," Lewis said Friday. "The primer would not have done any damage to an aircraft. It might have caused a fire, but it wouldn't have exploded."
The shell owner wasn't arrested, and he was given an opportunity to return it to a car, have somebody pick it up or have it shipped out of the airport.
He decided to abandon it with federal agents.
Meanwhile, arrests were made in the seizure of three other guns, all loaded with magazines of bullets, at the airport in the past week.
The recent spate of weapons came barely a week after the Transportation Security Administration reported it made fewer gun seizures at Utah airports in 2012 — 24, down from 27 the year before.
January brought "a spike for us," said Adams, who ruled out any malevolent intent by the gun owners but said she was concerned nonetheless.
Gun seizures at security check point back up other passengers in a hurry to catch their flights, she said. And officials said airline passengers should know the rules: no carry-on guns.
Most people caught with guns say they were unaware they had one in their hand bags. But a small minority tell agents that because they are licensed to carry a concealed weapon, they believed it was OK to walk a gun aboard an airline, Adams said.
All guns must be declared, unloaded, locked in a hard case, and — like swords — kept in checked bags, she said.
"We've been working on the awareness and thought we were being successful, but then we have this spike," Adams said. "We still have work to do."
Nationwide, the TSA said it seized more than 1,500 carry-on guns at airports in 2012.