Santos Cabilgan, an armed civilian volunteer in Nuangan, told investigators the second blast occurred near the Singao creek, at around 10 p.m.
Supt. Chino Mamburam, city police director, said the bomb that exploded in Nuangan was fashioned from an 81-mm mortar using a mobile phone as triggering device.
“The blast at the overpass and the explosion in Nuangan village were, in a way, connected to each other,” he said.
He added he ordered a manhunt immediately after the blast and that Nuangan was among the areas they searched first.
“The suspects could have planned another explosion in the city but ran out of time,” the official said.
A month earlier, Mayor Rodolfo Gantuangco said a male phone caller who claimed to be a leader of the so-called Al Khobar Group demanded money from the city government.
Gantuangco said the caller told him more explosions would rock the city if the local government did not give in to the demand.
On February 23, a homemade bomb went off at the pavilion of the city plaza here. Bomb experts said the explosive malfunctioned and exploded prematurely. (Malu Cadelina Manar/MindaNews)