Boko Haram gunmen killed 68 people, including many children, in a massacre in the northeast Nigeria village of Njaba, two witnesses and two vigilantes told AFP Thursday. "I participated in the counting of dead bodies. Sixty-eight people were killed," said Muminu Haruna, 42, after escaping the attack on Tuesday in the remote region.Children were deliberately targeted for slaughter and most of Njaba was destroyed by fire, Haruna and three others said.