WASHINGTON (AP) — Justice Department officials are turning to the 3D-printing industry to help stop the proliferation of tiny pieces of plastic transforming weapons into illegal homemade machine guns on streets across America.

The rising threat of what are known as machine gun conversion devices requires "immediate and sustained attention," U.S. Deputy Attorney General Lisa Monaco said Friday. That means finding ways to stop criminals from exploiting technology to make the devices in the first place, she said.

"Law enforcement cannot do this alone," Monaco said during a gathering in Washington of federal law enforcement officials, members of the 3D-printing industry and academia. "We need to engage software developers, technology experts and leaders in the 3-D-printing industry to identify solutions in this fight."

Devices that convert firearms to fully automatic weapons have spread "like wildfire" due to advancements in 3D-printing technology, according to Steve Dettelbach, the director of the Bureau of Alcohol, Tobacco, Firearms and Explosives. His agency reported a 570% increase in the number of conversion devices collected by police departments between 2017 and 2021.

"More and more of these devices were being sold over the internet and on social media, and more and more they were actually just being printed by inexpensive 3D printers in homes and garages everywhere," Dettelbach said.

The pieces of plastic or metal are considered illegal machine guns under federal law but are so small they run the risk of being undetected by law enforcement. Guns with conversion devices have been used in several mass shootings, including one that left four dead at a sweet sixteen party in Alabama last year.

The devices "can transform a street corner into a combat zone, devastating entire communities," Monaco said.

Monaco on Friday also announced several other efforts designed to crack down on the devices, including a national training initiative for law enforcement and prosecutors. The deputy attorney general is also launching a committee designed to help spot trends and gather intelligence.