The Transportation Security Administration expects to seize a record-high number of firearms this year, and is attributing the spike to an overall increase in air travel passengers.

"While it's impossible to ascertain an exact, scientific reason for the increase, there does seem to be a correlation between the increase in the number of firearms caught and the increase in passenger volume," TSA spokesman Mike England told the Washington Examiner. "2016 was a record year for passenger volume and the industry is on pace to break that record in 2017. The same can be said for TSA firearm catches."

The number of loaded and unloaded firearms apprehended by officers has increased every year over the past decade. In 2007, the Department of Homeland Security agency documented 803 guns discovered at airport checkpoints. That number ticked up a few dozen in the first year, then began climbing a few hundred each year after. By 2014, TSA reported 2,212 gun seizures and then 2,653 in 2015.

Last year, a total of 3,391 guns were confiscated, and 83 percent of those weapons were loaded with ammunition, according to government data.

The number of gun seizures is rising again this year. England said the agency had documented 3,053 firearms as of Oct. 10, with almost three months to go in the year.

In August, the Examiner reported TSA was on track to find 3,722 guns by the end of the year. However, since then, TSA has been finding more guns each week than expected. On an average day between January 1 and Oct. 10, officers seized 10.78 guns around the country. If that trend continues, TSA can expect to see 3,937 firearms confiscated by Dec. 31.

Air travel has been increasing along with gun seizures. TSA screens an average of 2 million people daily, and four of the 10 busiest-ever days for TSA took place in 2017. This past summer marked the busiest summer of all time with 239 million passengers screened.

Another TSA official said in August the spike was likely due to passengers' forgetting they had weapons on their person at the time of flying and not intentionally meaning to bring it to the airport.

"The number-one excuse that people give us for why they have their gun with them at a checkpoint is that they forgot that they had their gun with them. The second-most common excuse is that their husband or wife packed their bag. Neither of those excuses fly," TSA Acting Director of Media Relations Lisa Farbstein said.

Firearm possession laws vary with state and local laws. However, firearms must be unloaded and locked in a hard-sided container and transported as checked baggage.

All parts, including ammunition, must be declared at the airline ticket counter during the check-in process. Those who do not follow the law can be arrested and fined up to $11,000.