Authorities in northeastern Arkansas are trying to determine the cause of death for two newborn twins whose bodies were discovered inside of a suitcase along a rural road last week.

The bodies were found Friday in a purple suitcase on a ditch bank.

The Cross County Sheriff's Office says a preliminary autopsy found that the babies had a gestational age of about 32 to 34 weeks, or about six to eight weeks premature. They said one of the babies was a female. They were awaiting further testing for race, sex, time and manner of death.

The sheriff's office declined to release details on the investigation but said that several people have been interviewed and asked anyone with more information to call the Cross County Sheriff's Office at 870-238-5700.

The Associated Press contributed to this report.