The U.S. attorney for the Eastern District of Pennsylvania on Wednesday announced a federal lawsuit to have safe injection sites in Philadelphia declared illegal in a first-of-its-kind action in the nation.

U.S. Attorney William McSwain’s office had filed the lawsuit Tuesday, asking for a declaratory judgment that says safe injection sites, where heroin users can inject the drug under the supervision of medical staff, violates provisions of the Controlled Substances Act. The case, United States v. Safehouse, has been assigned to U.S. District Judge Gerald McHugh.