(WSB Radio) -- The FBI is looking for not one, not two, but three serial bank robbers that have hit a dozen metro Atlanta banks since August.

The FBI's Steve Emmett tells WSB they're most concerned about a duo of robbers who've hit six banks in a month.

"On the six occasions they've robbed, they've gotten money at each of these robberies, so it is totaling up to a pretty significant loss amount," said Emmett.

The first robbery occurred at a Wachovia bank in riverdale on October 13th, followed by a Suntrust bank in Forest Park, a Chase bank in Morrow, another Suntrust bank in Forest Park, and two RBC banks - one in Morrow, one in Jonesboro, on the same day, November 2nd.

"One of the robbers has a gold wedding band ring on his right index finger.  That's clearly displayed in one of the photographs," said Emmett.

Emmett says while they're suspected in those six, they could be responsible for a lot more.

The other serial bank robber, who works alone, has also hit six banks since August.  The robber hit five Wachovia banks in Stockbridge, Fairburn, Conyers, Riverdale, and Tucker.  He also hit a Bank of America in Stockbridge.

He's described as a black male, mid 30's, possible tattoo on his right forearm and on his neck, and a gold cap on a bottom tooth.  He may be driving a teal green Nissan Sentra with Georgia tags or a white four-door Kia/Nissan with drive out plates.

Anyone with information is asked to contact the Atlanta office of the FBI at 404-679-9000.