The unidentified flying object is NOT believed to be a plane as none have been reported missing in the area. Investigators are working on the theory the explosion happened five miles above the ground. A search of Phu Quoc island off southern Vietnam uncovered shards of grey “metal” up to four feet long. Unexplained explosion ... map showing island Soldiers combed the area for clues yesterday as airlines in Vietnam, Cambodia and Thailand insisted none of their aircraft were missing in the area. Villagers in the nearby Cambodian province of Kampot said on Tuesday that they had heard a...