Why can't the landmines be detected?

The main example would be "minimum metal" mines - a mine made mostly of something like plastic or wood is much harder to detect with a metal detector. Some mines have no metal at all, though that's pretty rare. read more

But to be totally correct, the world of landmines is a bit more perverted. So, yes there are mines which work on pressure release. But those are buried under other mines. So when a Deminer (like me and many of my friends) lifts a landmine out of the ground, there is a second one below which blows up upon the release of the weight. read more