Later, the initial barrier was built up into the Wall proper, the first concrete elements and large blocks being put in place on 17 August. During the construction of the Wall, National People's Army (NVA) and Combat Groups of the Working Class (KdA) soldiers stood in front of it with orders to shoot anyone who attempted to defect. Additionally, chain fences, walls, minefields and other obstacles were installed along the length of East Germany's western border with West Germany proper. A huge no man's land was cleared to provide a clear line of fire at fleeing refugees.