MIRANSHAH: A 12-year-old boy was killed in a landmine blast at Chinar Raghzai area in Dattakhel tehsil of North Waziristan tribal district, police sources said on Friday.The sources said that the boy identified as Islamullah, 12, was grazing cattle at Chinar Raghzai area in Dattakhel when he unknowingly stepped on an anti-personnel mine, which went off, killing him on the spot.