A group of Cambodians has made a documentary looking for the the mines and disarm them. Cambodia is famous for its civil war which Khmer Rouge, the communist party and the anti-communist forces fought against one another.
No one knows the exact amount of mines are being under the ground. According to the documentary, it seems so much easier to find a mine. It's one of the unsafe place to go around the jungle in Cambodia. And many people have died from those mines as well, mostly the innocent villagers.
Attached is the documentary of a group of Cambodian lookings for mines to disarm them.