The US Transportation Security Administration (TSA) has detected a record number of guns at airport check-ins so far this year.
By October, TSA officers had collected 4,495 guns from airline passengers - most of them loaded.
This is more than the previous record of 4,432 guns found over the whole of 2019, despite lower passenger numbers due to the coronavirus pandemic.
TSA chief David Pekoske said the number of firearms found was "alarming".
He said loaded firearms were an unnecessary risk at checkpoints, had 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".
However the TSA did not offer a reason for why people were trying to bring more guns onto flights.
While gun possession laws vary by state, airline passengers can travel with firearms in a checked bag when they are unloaded and locked in a hard-sided case. Travellers must also tell airline representatives that they intend to travel with firearms during check-in.
Firearms are not allowed in the passenger cabin on an airplane, even if a passenger has a concealed weapon permit.
If TSA officials detect a firearm at a checkpoint, they issue a civil penalty that varies by number of previous offenses and whether the gun was loaded at the time.