Some embodiments of the invention provide a dart that contains an HE payload, two time-delay fuses, one providing a relatively longer delay and the other providing a relatively shorter delay and two triggering mechanisms for triggering the fuses. The first triggering mechanism, which triggers on contact with a mine lid, triggers the relatively shorter time-delay fuse. The second mechanism, which triggers on overburdening exposure to water, sand, or soil, triggers the relatively longer time-delay fuse.