Two more men accused of participating in a string of jewelry store robberies across the South are facing federal charges in Florida.

The U.S. Attorney's Office in Panama City reports that 43-year-old Larry Gilmore and 46-year-old Michael Gilmore made their initial appearances Friday in Atlanta. The office said in a news release that the men had been charged with conspiracy to interfere with commerce by threats or violence.

Already facing charges were 24-year-old Abigail Kemp and 35-year-old Lewis Jones III. The FBI says Kemp and Jones stole an estimated $4.3 million in jewelry by robbing six stores in Georgia, Florida, North Carolina, South Carolina and Tennessee. Court filings allege Larry and Michael Gilmore provided surveillance and security for the crimes.

It wasn't immediately clear if the men were related. Court records didn't list attorneys for the men.