WASHINGTON (AFP) - An American man was arrested on Wednesday as he attempted to bring a gun into a congressional office building in Washington, police said, in the second such incident in five days.

"A firearm was recovered as a result of an administrative search at the entrance to the rotunda of the Cannon Building at approximately 0920 hours," said US Capitol Police spokeswoman Lieutenant Kimberly Schneider.

Ronald Prestage, 59, was arrested with a 9mm Ruger handgun and charged for carrying a pistol without a license.

Prestage is not a congressional staffer, unlike in Friday's incident when Ryan Shucard, press secretary to Republican Congressman Tom Marino of Pennsylvania, was arrested bringing a handgun and magazine into the same Cannon House Office Building.

Visitors to the Capitol complex and staffers with identification badges must walk through metal detectors at entrance points and put their bags and other belongings through an X-Ray machine.

In 2007, a senior aide to then senator Jim Webb was arrested for trying to bring a loaded pistol belonging to Webb into a Senate office building.