Police said the ski mask-wearing gunmen overtook the tricycle bearing Emy Manlulu, 43, and then shot her seven times with a caliber .45 pistol.
Manlulu was one of the campaigners of vice mayoral bet Emil Capati, a distant relative.
"We are looking into all possible angles, but as of now, we still have to find out the identities of the killers and their motives," said Senior Superintendent Rodolfo Mendoza, provincial police director. — Ding Cervantes, Ric Sapnu