Sources from the military’s intelligence community, however, said informants and some of the secessionist rebels are convinced that the bombing could be a "test mission" for a new batch of guerrillas being trained in handling explosives by the Jemaah Islamiya in a hinterland in Lanao del Norte.
Inspector Wally Kasuyo, spokesman of the city police, said investigators have yet to determine the identities of the bombers responsible for the attack here last Friday.
Kasuyo said the bomb was fashioned from three live 60 MM mortar projectiles rigged with an improvised timing device attached to a cellular phone.
"Fortunately, only one of the mortar rounds exploded and only three people were slightly wounded and only two were hospitalized," Kasuyo said.
Operatives of the 6th Explosives and Ordnance Detachment here said the bomb’s maker failed to rig the blasting mechanisms of each of the mortar rounds with a continuing circuit conductor to ignite all of it in one electrical spark.
"Because of such a deficiency, the improvised explosive turned out to be ‘low-level type,’ and failed to cause heavy damage. Thank God," said a bomb expert who asked not to be identified.
Chief Superintendent German Doria, director of the Region 12 police, said they are also looking into the possibility that the Jemaah Islamiya and the Abu Sayyaf could have jointly pulled off the blast.
The JI and Abu Sayyaf have been blamed for all the recent bombings in Central Mindanao, including the deadly Oct. 10 attack in Makilala, North Cotabato, which left six people dead and 32 others wounded.
Witnesses in Friday’s bombing here said a lone suspect casually left a box containing the explosive in a concrete wall between a small restaurant and an outlet here of the Jollibee hamburger chain and a small roadside restaurant, and hurriedly left.
The explosion shattered the front glass panels of the restaurant. Three vehicles parked about four meters away from the spot where the bomb was left were perforated with shrapnels.