The fatalities were 1Lt. Paulman Sadat Tamano and Pfc. Nabral Bara, both assigned to the Military Intelligence Battalion of the Armys 4th Infantry Division in Davao City.
Investigation showed that men on board a red Honda CRV and a red pick-up had tailed the two soldiers, who were riding in a Hi-lux pick-up, from Davao City.
Upon reaching Masterson Avenue in Upper Balulang here, the two red vehicles drove alongside Tamanos pick-up at about 1:20 p.m. and fired at it.
Tamano and Bara suffered multiple bullet wounds, killing them on the spot.
Investigators said the assailants used Armalite rifles.
Col. Francisco Simbajon, military spokesman, said the killings could be work-related or triggered by a clan feud.
Police investigators said it was possible that a "rido" motivated the attack, noting that the attackers apparently emptied their rifles on the two soldiers.
The police said they would first pursue this angle.
The military said it is conducting its own investigation into the ambush-killing.
Tamanos relatives in Marawi City discounted the role of the New Peoples Army (NPA) in the attack, saying that the vehicles used by the assailants were luxury vehicles.