Fewer Americans are taking to the skies because of the coronavirus pandemic, but they’re trying to bring along a lot more guns.

The number of firearms detected at airport checkpoints this year is already the highest in the 20-year history of the Transportation Security Administration. The agency says it has found 11 firearms in carry-on bags per 1 million travelers screened, up from just 5 per million in 2019.

The number of travelers violating gun rules has been rising over the years, according to data from the TSA, which was created in the aftermath of the Sept. 11 attacks. Typically, people can travel with firearms in their checked bags if the guns are unloaded and packed in a locked, hard-sided case.

“The number of firearms that our TSA officers are stopping at airport checkpoints is alarming,” TSA Administrator David Pekoske said in a statement. “Firearms, particularly loaded firearms, introduce an unnecessary risk at checkpoints.”

TSA officers stopped 4,495 passengers from carrying firearms onto flights as of Oct. 3, up from the 2019 record of 4,432. Most offenders were at the airport in Atlanta, followed by those in Dallas-Fort Worth and Houston.

It isn’t the only issue plaguing air travel this year. Americans have also contended with delays due to labor shortages and other factors such as inclement weather. This year, the number of unruly passengers on flights has also soared.