  We present a general procedure to construct 6-dimensional manifolds with
SU(3)-structure from SU(2)-structure 5-manifolds. We thereby obtain half-flat
cylinders and sine-cones over 5-manifolds with Sasaki-Einstein SU(2)-structure.
They are nearly Kahler in the special case of sine-cones over Sasaki-Einstein
5-manifolds. Both half-flat and nearly Kahler 6-manifolds are prominent in flux
compactifications of string theory. Subsequently, we investigate instanton
equations for connections on vector bundles over these half-flat manifolds. A
suitable ansatz for gauge fields on these 6-manifolds reduces the instanton
equation to a set of matrix equations. We finally present some of its solutions
and discuss the instanton configurations obtained this way.
