An appeals court will hear challenges to a District of Columbia law that places tough requirements for gun owners to get concealed carry permits.

A three-judge panel of the U.S. Court of Appeals for the D.C. Circuit is hearing arguments Tuesday in two cases involving the law, which requires people who want to carry a gun in public to show a "good reason to fear injury" or another "proper reason" to carry the weapon. Reasons might include a personal threat, or a job that requires a person to carry or protect cash or valuables. Lower court judges have disagreed on whether the law is constitutional.

The hearing is the latest in a long-running tussle over the city's gun laws. Eight years ago, the U.S. Supreme Court struck down the city's ban on handguns, leading the city to rewrite its gun laws. City law now requires residents to register guns kept at their homes or businesses; more than 16,500 guns have been registered, according to police.

Anyone who wants to carry a weapon outside the home needs a separate concealed carry license. The police department said last week that 89 people have been granted concealed carry permits and 374 have been denied.

In March, U.S. District Court Judge Colleen Kollar-Kotelly sided with the city and declined to issue a preliminary injunction halting the enforcement of the law requiring a "good reason" or "proper reason" for anyone who wants to carry a gun in public. Kollar-Kotelly said opponents had not shown that their lawsuit was likely to be successful. She noted that appeals courts in other parts of the country had approved of laws in New York, New Jersey and Maryland that are similar to the District of Columbia's.