Capitol Police said that a man was arrested on Tuesday after he brought one or more weapons to the U.S. Capitol.
"USCP Officers just arrested a man with a gun in the park across from Union Station. At this time we have no reason to believe there is an ongoing threat," Capitol Police said in a statement. "We are working to gather more information and will put out more details when they are confirmed."
NBC's Frank Thorp V reported that one source said the gun was an "AR-15" assault-style rifle.
Capitol Police later confirmed to Fox News that the weapon was an AR-15.