  In this work we give a complete description of the set covering polyhedron of
circulant matrices $C^k_{sk}$ with $s = 2,3$ and $k\geq 3 $ by linear
inequalities. In particular, we prove that every non boolean facet defining
inequality is associated with a circulant minor of the matrix. We also give a
polynomial time separation algorithm for inequalities involved in the
description.
