Probers said former mayor Felix Frayna was campaigning with his supporters in Barangay San Eugenia at about 8 a.m. when two men shot him.
Wounded were former policeman Ulysses Friles, Fraynas campaign manager, and a certain Renato Estillada. They were rushed to the Sorsogon Provincial Hospital.
Investigators suspect that the attack had something to do with Fraynas refusal to pay a "campaign fee" ranging from P150,000 to P200,000, which the New Peoples Army (NPA) has set for politicians running for municipal mayor in the region.
In a related development, a candidate for councilor in Ocampo, Camarines Sur was reported to have been abducted by two armed men.
Police said Miguel Butin, a barangay chairman who is seeking a council seat under the People Power Coalition ticket, was forced to board a black Suzuki motorbike which headed toward Barangay Hancusan.
In Palanas town, meanwhile, six armed men wearing ski masks strafed the house of Joseph Avila, head of Barangay Malibas. No one was hurt in the attack.