Five people, including a three-year old boy, were killed when a bomb exploded outside a church in the southern Philippines. The bomb went off as an army truck passed by; a soldier was among the victims, as was a woman selling food from a road-side stall.The attack in Cotabato City on Mindanao island is the latest by Muslim rebels fighting for independence. Violence has soared in recent weeks. Police said the crude bomb was made from a mortar and was detonated by mobile phone. It was placed across the street from a church and exploded during mass. Local Archbishop Orlando Quevedo denounced the attack as sacrilege. Mindanao is believed to be sitting on top of valuable oil and gas reserves. But the island remains impoverished with the violence scaring away potential investors.