The title of this set of photos from the Flickr photo stream of Clear Path International is "Hobby De-Miner". Clear Path International is a non-profit devoted to serving the survivors of landmines. As the unnamed photographer explains, "We ran into this boy collecting scrap metal from the Vietnam War alongside the road near Da Nang. Often, while searching for scrap, people that do this will find a bomb and attempt to dismantle it and sell the metal. Many are killed or injured."
The equipment apparently works. Here is a piece of iron found and recovered.