Reports reaching the Autonomous Region in Muslim Mindanao (ARMM) police identified the slain politician as Biden Galif, former vice mayor of Panglima Sugala town, some 20 kilometers away from Bongao, the provincial capital.
Police confirmed that two security escorts of Galif were also killed in the firefight.
Galif and his followers, armed with assault rifles, reportedly surrounded the house of a political rival, Amil Asarun, an incumbent barangay councilman, thus provoking the gunbattle.
Asarun and his younger brother Birong were both wounded in the incident.
The hostilities forced residents to flee their homes.
Senior Superintendent Akmad Mamalinta, ARMM police director, said Tawi-Tawi Gov. Sadikul Sahali is now initiating moves to amicably settle the clan war.