A Georgia man fled the state last week with his three young children and sent a letter to his father stating that he was going to kill the kids, the FBI said Tuesday as it sought public assistance in locating the suspect.

Eddie Harrington, 28, has been missing from the Columbus, Ga., area since at least March 6, when authorities in Tennessee issued a child abduction alert after he may have been spotted there.

He is believed to be traveling with his twin 23-month-old girls, Aliyah and Agana Battle, and his 3-year-old son, Cedric Harrington, FBI agent Stephen Emmett said.

At some point, Eddie Harrington sent a letter to his father in the Indianapolis area "indicating he was going to kill the kids," Emmett said.

Columbus police issued a felony child endangerment warrant for Harrington, and the FBI on Monday issued a federal unlawful flight to avoid prosecution warrant because he is believed to have left the state.

An FBI advisory announcing a news conference Wednesday to provide photos and release more details about the case says that Harrington has connections to the Indianapolis area and is believed to be headed there.

Harrington is believed to be driving a 2002 Chevrolet Impala with Indiana tags.

Emmett said he doesn't know what sparked Harrington's decision to flee with his children.