PHOENIX - Federal officers have detected a record number of guns at airport security checkpoints this year, with Phoenix among the hot spots.

The Transportation Security Administration had already stopped 4,495 passengers from taking firearms onto planes as of Oct. 3, the most in at least 20 years, the agency announced Wednesday.

Guns have been discovered in 248 different airports, with Phoenix Sky Harbor International Airport ranked fourth with 147. Hartsfield-Jackson Atlanta International was No. 1 with 391, followed by Dallas/Fort Worth International with 232 and George Bush Intercontinental in Houston with 168.

The 2021 total surpassed the single-year record of 4,432 from 2019 even though fewer people are flying this year. Phoenix was fifth overall in 2019, with a then-record 132 guns.

For every million passengers screened at checkpoints across the nation in 2021, TSA officers have found 11 guns in carry-on bags. The rate in 2019 was five guns per million screenings. The 2020 rate jumped to 10 per million.

"The number of firearms that our TSA officers are stopping at airport checkpoints is alarming," TSA Administrator David Pekoske said in a press release.

"Firearms, particularly loaded firearms, introduce an unnecessary risk at checkpoints, have no place in the passenger cabin of an airplane, and represent a very costly mistake for the passengers who attempt to board a flight with them."

Violators face fines of $1,500 to nearly $14,000, with repeat offenses and loaded weapons drawing higher penalties, as well as possible criminal referral.

Airline passengers who want to travel with firearms are permitted to do so in checked baggage. The guns must be unloaded and locked in a hard-sided case and declared during the check-in process.