Authorities on Saturday morning recovered two rifle grenades on a roadside in Baliwasan Seaside, Zamboanga City.
Bomb experts detonated the explosives, which police believe may have been thrown or left in the area.
Investigation is ongoing to determine who owned the explosives and why they were left on the road.
In August, local authorities reported a bomb threat from the alleged mastermind of the Aug. 24 deadly blasts in Jolo, Sulu.
— Report from Queenie Casimiro