Abstract: An applique armour panel for fitting to a substrate and for protecting the substrate from missile or other projectile attack which panel comprises an exterior plate (1), an interior plate (4) and a layer or layers (7) of explosive material therebetween. The explosive material is detonated by an incoming missile to cause disruption of the incoming missile and reduce its penetrative effect. The panel is constructed so that upon reactive explosion the interior and exterior plates are driven apart more rapidly at one edge of the panel than at an opposite edge by a rotating moment of one plate relative to the other.