Two men are now facing federal charges after authorities say they were found with machine gun conversion devices—also known as “switches.”

The incidents happened separately but were both linked to Twin Cities high school graduation ceremonies.

Hamza Abdirashiid Said, 20, and Amiir Mawlid Ali, 18, were each charged this week in U.S. District Court with unlawful possession of a machinegun. Both remain in federal custody following their initial appearances on Tuesday.