BARTOW, Fla. (AP) - Central Florida authorities are investigating the death of a jail inmate.

Polk County Sheriff's detectives say 46-year-old Gerald Jacobs died early Saturday at a hospital.

According to a sheriff's report, Jacobs began complaining of severe stomach pains. He was transported to the jail infirmary and then to a hospital, where he died.

An autopsy was scheduled Sunday to determine the cause of death. The sheriff's office has begun an internal review of Jacobs' death.

Authorities say Jacobs was serving a 120-day sentence in the Polk County jail for one count of violation of probation battery domestic violence and one count of violation of probation resisting arrest without violence.