A U.S. appeals court has ruled that parts of a law banning guns in Washington, D.C. are unconstitutional.

Friday's ruling, decided in a two to one vote, struck down a provision that bans residents of the nation's capital from keeping handguns in their homes. The court said the ban violates the Second Amendment of the U.S. Constitution.

The amendment grants "the right of the people to keep and bear arms" and allows for a "well regulated militia."

The court also struck down a section of the law that requires owners of legally registered guns to disassemble them.

The city's anti-handgun law, passed in 1976, is one of the most restrictive in the United States. Mayor Adrian Fenty said he is outraged by the appeals court decision, and vowed to appeal the ruling.

If the case goes before the U.S. Supreme Court, as expected, it would be the first time the high court would hear a Second Amendment case since 1939.

The amendment is a single sentence that reads "A well regulated militia, being necessary to the security of a free state, the right of the people to keep and bear arms, shall not be infringed."