Washington (AFP) - The US Supreme Court heard a gun rights case for the first time in nearly a decade on Monday but may decide to dismiss it without issuing a ruling.

The nine justices on the nation's top court heard arguments in a case involving gun restrictions imposed by New York, which has some of the toughest gun laws in the country.

Backed by the National Rifle Association (NRA), the powerful gun lobby, opponents filed suit against the restrictions claiming they violated the Second Amendment to the US Constitution, which enshrines "the right of the people to keep and bear arms."

Lower courts upheld the New York City law barring people from carrying guns outside their home except to seven firing ranges in the city.

Opponents argued that the law violated their rights by prohibiting them from taking their weapons to a second residence or shooting ranges outside New York City.

The Supreme Court took up the case but New York repealed the law in June, a move which lawyers for the city argued on Monday renders the case moot.

The argument appeared to hold sway with the liberal justices, who are outnumbered 5-4 on the Supreme Court by conservatives.

"So what's left of this case?" asked Ruth Bader Ginsburg, one of the four liberal justices.

"What you're asking us to do is to take a case in which the other side has thrown in the towel," said another liberal justice, Sonia Sotomayor.

Conservatives unconvinced

The conservative justices appeared unconvinced.

"Why isn't there a live controversy remaining?" asked Justice Neil Gorsuch, who was appointed to the court by President Donald Trump.

Paul Clement, a lawyer for the New York State Rifle & Pistol Association, argued that the Supreme Court needs to intervene.

"The Second Amendment protects rights that are not strictly limited to the premises," Clement said.

Guns kill nearly 40,000 people a year in the United States and this is the first gun control case before the Supreme Court in nearly 10 years.

In a landmark decision in 2008, the court ruled that the Second Amendment guaranteed what it called an individual right to own a gun, and struck down a law that banned handguns in the nation's capital.

In 2010, it said the decision applied both at the state and federal level.

"But it has not said very much about how courts should evaluate the constitutionality of other gun laws, such as restrictions on assault weapons, high capacity magazines, and concealed carrying," said Joseph Blocher, a Duke University law professor.

Defenders of stricter gun control laws are afraid the court will issue a ruling that undermines their cause.

Shift to the right

The court has undergone a marked shift to the right under Trump, who promised during the 2016 campaign to nominate judges who support gun rights.

Since taking office, he has filled two Supreme Court vacancies with conservative jurists.

One Trump appointee, Brett Kavanaugh, has written in prior opinions that gun laws should be evaluated "solely on the basis of text, history, and tradition, rather than their effectiveness in addressing contemporary problems of gun violence," said Blocher.

The case is drawing attention in a country in which 30 percent of the adult population owns at least one gun. Around 50 organizations filed friend-of-the-court briefs.

The Trump administration supported the gun rights side by filing a brief that echoes arguments Kavanaugh has made.

On the other side, an organization called March for Our Lives -- founded after a school shooting last year in Parkland, Florida, that left 17 people dead -- skipped legal arguments and is trying to win over the justices with emotional accounts of the ravages of gun violence.

In a lengthy brief, it detailed the suffering of young people from the epidemic of gun violence, recounting, for example, how a student survived a shooting by hiding under a slain friend's body.

If the court does not declare the case moot, it will hand down a decision by June, with the 2020 presidential election campaign well underway.