Fecha de publicación: 31/08/1983 Fuente: WIPO "royal booby" A land mine is provided with a magnetic field sensing device which is arranged to initiate detonation of the mine when a change in the magnetic field is sensed. A magnetic body is laid out loosely underneath the mine so that when the mine is raised from the ground this results in the mine being removed from the magnetic body, so that a change in the magnetic field which initiates detonation of the mine is sensed by the magnetic field sensing device.