A grenade blast killed seven children at a school in Ivory Coast after a pupil found the device nearby and removed the pin while playing, ANTARA quoted local authorities as saying on Wednesday. The boy, who was killed instantly, and a friend had found two grenades near a school in the northeastern town of Bondoukou, local health worker Clement Assi said. The other boy had taken the second device home to his father, who handed it in to the police, he said. "The age of the children killed is between around 4 and 15 years. Among the injured, two were seriously hurt and five only slightly," Assi told Reuters. Local police confirmed the incident and said an inquiry was under way.