The Supreme Court on Tuesday agreed to freeze a lower court order that bars the government from regulating so-called ghost guns -- untraceable homemade weapons -- as firearms under federal law.

The brief order grants the Biden administration's request to allow the regulations to remain in effect while legal challenges play out.

Ghost guns are kits that a user can buy online to assemble a fully functional firearm. They have no serial numbers, do not require background checks and provide no transfer records for easy traceability. Critics say they are attractive to people who are legally prohibited from buying firearms.

The vote was 5-4. Justices Clarence Thomas, Samuel Alito, Neil Gorsuch and Brett Kavanaugh would have denied the application.

This story is breaking and will be updated.