Col. John Cherrie, commander Davis-Monthan Air Force Base on the outskirts of Tucson, says officials were satisfied that the base was safe again after an extensive search at the base.
Cherrie held a two-minute news conference to discuss the five-hour lockdown of the base on Friday. He didn't answer any questions by reporters.
A military official had said earlier that a man with a gun was holed up in a building at the base.
The lockdown at the sprawling facility was prompted by reports of someone with something that looked like a weapon.
The reports prompted a frenzy of activity at the base and in the news media amid unsubstantiated reports that someone had been shot.