ATLANTA — Federal prosecutors charged four Fulton County jailers on Thursday with smuggling drugs and cellphones into the facility, raising concerns about the jail’s security a week after an inmate was wounded by a bullet fired from a small gun that was found in the building.

U.S. Attorney Sally Quillian Yates said the federal charges aren’t linked to the gun found inside the Atlanta jail, but Sheriff Ted Jackson said the incidents have forced him to tighten security inside the complex.

“Some of the employees are conflicted,” said Jackson. “They don’t know which side of the bars they belong on. We’re going to help them make that decision.”

Sheriff’s Deputy Marvie Trevino Dingle and detention officers Brian Shelby Anthony, Akil Scott and Derick Deshun Frazier have all been charged with extortion after prosecutors said they accepted cash payments to deliver the contraband to inmates inside the jail. The four were arrested at morning roll call.

Four others who are not officers were charged with distributing cocaine outside the jail. They are Aqeel Muhsin Rasheed, Keithan Henri James, Robert Lee Swain and Rayfield Lewis II.

Attorneys for the eight men were not immediately identified in court documents.

Jackson, a former FBI agent who was elected in 2008, has not been shy about pressing for federal scrutiny of his jail. He said he asked federal authorities to launch an investigation into his jail last summer after he realized there was a growing contraband problem inside the walls.

FBI Special Agent in Charge Brian Lamkin praised Jackson for giving his agents “unfettered access” to the jail, and the initial results of the investigation were released Thursday in court documents.

Anthony, one of the detention officers, is charged with accepting almost $27,000 in a deal with Rasheed, James, Swain and Lewis to buy at least five kilograms of cocaine. He’s also accused of taking bribes to deliver marijuana to an inmate.

The other two detention officers face charges of taking bribes to facilitate drug deals and delivering phones and cigarettes to inmates. And Dingle, the sheriff’s deputy, took at least $2,000 to distribute hundreds of grams of cocaine, prosecutors said.

It’s at least the second time Jackson has called on federal investigators to probe his jail. Two lieutenants, Robert W. Hill and Earl Glenn, were charged in 2009 with using excessive force against an inmate and then lying about it. Glenn pleaded guilty to the charges, and Hill was convicted after a jury trial.

The jail has also faced more scrutiny since an inmate was shot in the hand inside the jail on June 21 with a small gun that was no bigger than a cellphone. Yates said prosecutors are investigating how the weapon got inside the facility.

The security woes led Jackson to step up security. Jail officers are going through more intense screening each time they enter the building, he said, and he’s already implemented psychological evaluations and polygraph tests for new hires. He said the four officers who were charged Thursday were hired before the new standards were adopted.

Lamkin, the FBI agent, said officers who violate their oaths should be rooted out.

“The greatest harm, however, is that to the public trust, which makes the work of the rest of the criminal justice community even more difficult,” he said.