Guatemalan officials say an army captain sentenced to 20 years in prison for the slaying of a bishop has been arrested outside the facility where he was living.

Byron Lima was sentenced in 2006 along with three other men for the 1998 killing of Bishop Juan Jose Gerardi. The activist clergyman had released a report accusing Guatemala's military of being responsible for the vast majority of deaths during the country's brutal 36-year civil war.

Lima was driving an armored SUV Friday evening along with the director of the prison where he was living. Five prison guards were protecting them in a second armored vehicle.

Lima told the press he was being taken to a dental appointment. Officials said his exit from prison was not a jailbreak, but a violation of regulations.