DW: Mr Pitzke, you were most recently in Libya working as a landmine clearer. What exactly was the situation there?

Gunder Pitzke: We were involved in improving the safety levels at the airport in Tripolis. There were very small mines there, non-metallic and with 50 grams of explosives. These anti-personnel mines had been placed on the sides of the airport, in order to stop people from accessing the site. The area wasn't marked or surveyed. When these sorts of munitions are being used in civil wars, it's a violation of international human rights law.

How do you know where to search for the mines?

At the start we just have areas of suspected contamination. Reports come into the Mine Action Center saying that something has been discovered. Then we go there and check out the area. You have to be very careful and alert, because you never know where the mine field actually starts. Once you have achieved a safety line, then you start searching in strips. Firstly, you search it visually. If you see something suspicious, like packaging material from mines, then the surveying and securing of the whole area begins.

And how exactly do you disarm a mine?

We use needle-shaped mine detectors or metal detectors to look for objects buried under ground. Once we find them, they are carefully exposed and inspected to see what type of mine it is. Then we look at the construction and at the amount of explosive material. And then we try to extract the mines one by one.

If we detonated a mine immediately, other mines nearby could detonate or change their state. Then we would have start the whole search all over again. So instead, the mines are removed and they are exploded somewhere else at the end of the day.

How hard is it to detect mines?

The mines used these days have just a small amount of metal in them. Metal makes up maybe 0.3 percent of the mine – in some cases it's just the firing pin that's metal. If the surface of the searched area contains metal debris, nails or other metal scrap near the surface, then the metal detector signals coming from the other objects are stronger than from the mines themselves. Then you have to dig out and expose each and every object, until you really find the mine.

Do these sorts of devices become less dangerous over time?

No, it's the opposite actually. Mines become more dangerous the older they get. A landmine always contains an amount of TNT or another explosive mixture, RDX. These explosives lose their flexibility over time, making the material become unstable. Sometimes a bit of friction will be enough to cause the detonation. That means these mines can be in the ground for 80 or 90 years and still be dangerous.

Look at the example of Verdun in France, the battlefield in the First World War. The explosives there are still active. The firing pins are rusted and don't work, but it's definitely still possible that the mines explode.

Your work is obviously very dangerous. How high is the risk that something could happen?

Of course bad things happen every now and then. Those are the things that you actually don't like to talk about. After all, you know the people involved, you've given them the training.

An example which I experienced in Afghanistan: an American colleague was using a mine clearing device and moved in front of the machine, but between the tracks that had been checked. At that point he stepped on a mine. There are many examples like this. It's always very bad for everyone involved, but there is always some risk there in the work we do.

Gunder Pitzke is a retired captain in the German Army. Until 2008 he taught at the German Army engineering school formerly in Munich, specializing in mine clearance. Pitzke has worked in Libya, Afghanistan and Bosnia and has trained mine clearers in each country.