I stayed near Dubrovnik in the summer of 2005. There was a wildfire burning on on the hills behind us.
The fire traversed the hillside, and every hour or two a landmine would explode.
This was ten years after the war.
Sounds like the cheapest way to remove mines from land.
10 years is a long time, but 10 years after a war is not a long time. Damages to building still remains, mines and plenty of unexploded ordinances will remain, and psychological scars are still very strong.