Police said the victim, Rolando Cañete, 60, a former part-time broadcaster, died on the spot from three gunshot wounds.
The assailants, according to police, drew up beside Cañetes motorcycle driven by his son in the downtown area and shot him with a caliber .45 pistol. Cañetes son was unharmed.
Reports said Cañete was on his way to the provincial Capitol when he was killed at about 9 a.m. near the Kawit Bridge.
Cañetes attackers were wearing ski masks, reports said.
Police were investigating possible political or personal motives behind the killing.
Cañete had daily radio programs on three radio stations, two of them controlled by the Cerilles couple, where he frequently criticized their political opponents, residents said.
Rudy Dagumo, news director of Smile Radio in Pagadian City, said Cañete used to be a "blocktimer" who paid for his airtime on RMN dxPR and Radio Bagting, owned by the Cerilleses, before he worked in the congressmans congressional district office in Zamboanga del Sur. With Richel Umel, Cecille Suerte Felipe and AFP