Danish scientists have genetically engineered a weed that turns red when its roots encounter explosive material. It could revolutionise landmine clearance operations in countries like Cambodia.

The plant, arabidopsis thaliana (or green wall cress), is undergoing testing at Copenhagen University according to the Copenhagen Post newspaper. Molecular biology professor John Mundy, a consultant on the project, says: "If we invest the right resources in more research, I have no doubt that this plant will be able to be used to locate landmines in Africa within the next couple of years."

There are an estimated 100 million undetected landmines in the world, in 75 countries.