"Between the outbreak of the fighting on January 11 and yesterday evening, the number of dead totalled 88," Abdallah Ouheida told AFP.
The fighting erupted between members of the Toubou minority, a non-Arab ethnic group, and armed Arab tribesmen of the Awled Sleiman.
There has since between fighting between the Awled Sleiman and other Arab tribes that is reported to have involved supporters of slain dictator Muammar Gaddafi.
Libya's General National Congress declared a state of emergency in the south on January 18 at an extraordinary session convened to discuss the violence in Sebha.