A number of 3D-printed guns and related firearms have been found at airport security checkpoints across the US in the past two years, together with several other types of weaponry, the US Transportation Security Administration (TSA) has revealed.

Speaking to CBS News, the agency said that there have been at least four cases of confiscation of such weapons since 2016.

The news comes in the wake of a court battle taking place in Seattle over the downloading of blueprints for 3D-printed guns. Access to these blueprints was made available last week by gun access advocacy group Defense Distributed. The move was heavily criticised across the country and led to eight states suing the Trump administration in a bid to block the blueprints from being commercialised.

TSA assistant administrator Michael Bilello said in a statement to CBS News: “TSA officers are trained and on the lookout for 3D guns. We have proven detection capabilities and screening protocols in place. In the world of airport and aviation security, ‘a gun is a gun.'”

According to the agency, the first case involving 3D guns took place in August 2016, when officers found a “3D-printed realistic replica revolver” and ammunition at Nevada’s Reno-Tahoe International Airport.

Another 3D-printed weapon was confiscated from a carry-on bag at Manchester-Boston Regional Airport in New Hampshire in May 2017, while the other two cases, which took place in December 2016 and January 2018, involved 3D-printed parts of assault-style weapons known as ‘lower receivers’ at Las Vegas’ McCarran International Airport.

The TSA said that the majority of weaponry recovered was not made using a 3D printer. The agency added that 3,957 guns were found in carry-on bags in 2017 at an average of 10.8 firearms per day.

However, despite these statistics, CNN revealed today that the TSA is considering the elimination of passenger screening at over 150 small and medium-sized airports across the US. The move could save $115m every year, though has raised concerns about national security from both members of the public and TSA officials.