Authorities say a 911 call led to the dismantling of an Atlanta area sex trafficking ring involving at least four girls between the ages of 14 and 16.

Four men have been arrested, police said Friday, and detectives are still searching for a fifth suspect believed to be involved.

The investigation started in late February when a 15-year-old girl who had been reported missing sought help at a “place of refuge,” Atlanta police investigator Tracy Lewis said.

During a subsequent police interview at an Atlanta children’s hospital, the teen told detectives she had been held against her will and trafficked for sex, Lewis said, noting the alleged victims were forced to “service” men at gas stations, truck stops and other places.

Authorities said they identified two places where the victims were allegedly kept, one in DeKalb County and one in Atlanta. Investigators said the 15-year-old was particularly helpful because she watched crime shows on TV and knew to provide the police with addresses and license plate numbers.

“She was absolutely wonderful,” Lewis said. “She was very, very knowledgeable about what was going on. She made sure that she remembered things.”

Because the alleged trafficking occurred in two counties, the case is being investigated by multiple jurisdictions, including the Atlanta and DeKalb police departments and the Fulton and DeKalb district attorney’s offices.

Those arrested so far include Albert Wells, Talmes Eugene Smith III, Taalib Blount and Levi Jackson Sears, authorities said. A fifth suspect, Harold Poole, is still at large.

Wells, 23, is charged with rape, trafficking a person for sexual servitude and enticing a child for indecent purposes, among other crimes. Smith, 48, faces charges including rape, tracking a person for sexual servitude child molestation and two counts of contributing to the unruliness of a minor.

Blount, 47, faces eight charges, including rape, aggravated assault, sex trafficking, sodomy and aggravated child molestation, according to police. He’s also charged with false imprisonment and two counts of contributing to the unruliness of a minor.

Sears, 22, is charged with rape and child molestation. Poole, who has not been arrested, faces charges that include rape, aggravated assault, sex trafficking and aggravated child molestation, among other offenses. He is 40.

“Traffickers prey on the most vulnerable people in our community, people who oftentimes feel like they have no one to trust and nowhere to turn,” said Casey Benton, an investigator from the DeKalb DA’s office who focuses on human trafficking cases and internet crimes against children.

Detectives said the case is ongoing and urged anyone with information to call Crime Stoppers at 404-577-8477. Tipsters can remain anonymous and receive rewards of up to $2,000 for their assistance.