A bomb went off yesterday afternoon in Narathiwat province, injuring a member of a seven-man teacher protection unit. The explosion occurred on a village road in Chanae district as the unit was returning to its base.Volunteer ranger Adithep La-ongsri was injured by the blast which almost blew his left leg off. Sgt Preecha Pikhiri, the unit leader, said he and his men were on foot when the bomb exploded. They had just escorted a group of teachers home.