The legislation makes it a state crime to possess the devices, which turn semi-automatic firearms into automatic ones.

Alabama Governor Kay Ivey signed into law a bill banning Glock switches and other conversion devices that convert semi-automatic weapons into machine guns.

The Birmingham mayor, who lost a brother and nephew in shootings, has expressed frustration over gun violence in his city. Police say the devices produce a rapid, hard-to-control spray of bullets that increase the number of casualties during a shooting.