Fulton County Sheriff Ted Jackson confirmed Saturday that the county jail was on lockdown during the day after staff found a weapon among inmates.

The jail was on lockdown for several hours as staff conducted what officials described as an extensive search.

“This shakedown did result in the discovery of some contraband, including a shank, which is defined as a homemade weapon,” a news release about the incident said. The search did not turn up any firearms, the release said.

Civilian staffers were evacuated during the search. “No one was injured,” the release said. “No employees, no inmates, no visitors were in danger at any time.”

Atlanta Police also were called to the scene and blocked entrances during the incident.

The jail has been the target of a recent investigation into contraband and weapons being found at the lockup.

Earlier this month FBI agents arrested a sheriff's deputy and three detention officers following a nearly year-long sting to Sheriff's Office employees facilitating the transfer of contraband into the jail.