People under the age of 21 have been ruled not sufficiently "responsible" to legally buy handguns in the United States.
The US Supreme Court has refused to review restrictions on handguns for young people, dealing a blow to gun lobbyists.
The highly-awaited decision by the court, delivered without comment on Monday, dismissed two challenges by the powerful National Rifle Association.
The move upholds a Texas law that prevents young people aged 18 to 21 from obtaining a permit to carry handguns. It also confirms a 1968 federal provision that only allows the sale of handguns to those older than 21.
In both cases, a federal appeals court had raised doubts - in two separate rulings - that the age group was sufficiently "responsible", even though the Second Amendment to the US Constitution protects the right of individuals to keep and bear arms.
Last month, the Supreme Court heard arguments in a case about legal provisions intended to prevent the "straw" purchases of guns by one individual for other buyers.
That followed a January 15 hearing on whether domestic violence offenders could be barred from possessing a firearm even if they have only committed minor offences.
The court has yet to issue rulings in either case.
