The Transportation Security Administration said Tuesday that it detected twice as many firearms per million passengers at airport security checkpoints in 2020 than it did in 2019.

The agency announced that it found about 10 firearms per million passengers screened last year, compared with about five firearms per million passengers screened a year earlier.

Though the number of firearms found decreased — 3,257 in 2020 compared with a record 4,432 in 2019 — the rate per passenger was the highest since the agency was founded in 2001. About 83 percent of the firearms found were loaded, the TSA said in a statement.

The increased rate came during a year of substantially less air travel amid the coronavirus pandemic.

Darby LaJoye, executive assistant administrator for TSA security operations, commended officers for catching the weapons at checkpoints.

“Firearms are strictly prohibited onboard planes in the passenger cabin,” LaJoye said in a statement. “Bringing a firearm to a TSA security checkpoint poses a serious risk to TSA officer and passenger safety.”

Firearms were found at more than 230 airports across the country, the agency said. Those who bring firearms to a checkpoint may face arrest or fines of more than $13,000.

There were 220 weapons detected at Atlanta’s Hartsfield-Jackson International Airport, the most in the country. The top 10 list:

1. Hartsfield-Jackson Atlanta International Airport (ATL) 220

2. Dallas/Fort Worth International Airport (DFW) 176

3. Houston’s George Bush Intercontinental Airport (IAH) 126

4. Phoenix Sky Harbor International Airport (PHX) 124

5. Denver International Airport (DEN) 104

6. Nashville International Airport (BNA) 94

7. Fort Lauderdale-Hollywood International Airport (FLL) 87

8. Orlando International Airport (MCO) 79

9. Las Vegas McCarran International Airport (LAS) 72

10. Salt Lake City International Airport (SLC) 71

While Washington-area airports did not make the top 10, Baltimore-Washington International Marshall Airport recorded the most weapons detected in the region last year, as it has since 2017.

The agency explains how to travel with a firearm on its website.