State and local police in south Georgia are involved in a frantic search for a Marietta couple who disappeared after going to purchase a car from a seller they contacted online.

Telfair County Sheriff Chris Steverson said the Georgia State Patrol's aviation unit has joined local officials searching Telfair and Wheeler counties for Bud and June Runion, who are both in their late 60s.

The couple drove to McRae on Thursday to meet someone who responded to an ad Bud Runion placed on Craigslist seeking a 1966 Mustang. The Atlanta Journal-Constitution reports that family members became concerned when the couple did not return for a family function and did not answer their cell phone.

Concerned family members have set up a Facebook page to assist with the search and to raise awareness of the couple's disappearance.

Police say the phone number the Runions called traces back to a disposable cell phone, signals from which they are tracking in hopes of finding the couple. A missing person's report has been filed with Cobb County police.

The Associated Press contributed to this report.