A federal appeals court on Tuesday ruled a Minnesota law requiring a person to be at least 21 years old before obtaining a permit to carry a handgun in public for self-defense is unconstitutional.

The St. Louis-based 8th U.S. Circuit Court of Appeals sided with gun rights groups in finding the state's ban violated the rights of 18- to 20-year-olds under the U.S. Constitution's Second Amendment to keep and bear arms.

U.S. Circuit Judge Duane Benton, writing for a panel of three judges all appointed by Republican presidents, held that under recent U.S. Supreme Court rulings that have expanded gun rights, the state's 2003 law could not be deemed valid.

"Importantly, the Second Amendment's plain text does not have an age limit," he wrote.

The panel upheld a lower-court judge's ruling last year in favor of the Second Amendment Foundation, the Firearms Policy Coalition and the Minnesota Gun Owners Caucus, gun rights groups which had sued alongside some of their members.

Gun rights groups have filed similar lawsuits challenging age-based restrictions on carrying firearms in other states, including in Georgia, Illinois and Pennsylvania.

Benton cited a landmark 2022 ruling by the U.S. Supreme Court's conservative majority called New York State Rifle & Pistol Association v. Bruen that changed the landscape of firearms regulation.

That ruling established a new test for assessing firearms laws, saying restrictions must be "consistent with this nation's historical tradition of firearm regulation."

In June, the Supreme Court in an 8-1 decision in United States v. Rahimi clarified that standard when it upheld a federal ban on people under domestic violence restraining orders from having guns, saying a modern firearms restriction did not need a "historical twin" law.

Citing that decision, Benton said a regulation disarming people who pose a credible threat to others' physical safety could be upheld, but Minnesota had not established why 18- to 20-year-olds posed particular risks that justified its law.

Minnesota Attorney General Keith Ellison, a Democrat whose office defended the law, in a statement said he was "extremely disappointed" by the ruling.

"The people of Minnesota want and deserve solutions that reduce shootings and improve public safety, and today's ruling only makes that more difficult," he said. (Reporting by Nate Raymond in Boston; Editing by Alexia Garamfalvi, Richard Chang and Rosalba O'Brien)