The main result of this paper is that point sets of PG(n, q 3), q = p h , p ? 7 prime, of size less than 3(q 3(n?k) + 1)/2 intersecting each k-space in 1 modulo q points (these are always small minimal blocking sets with respect to k-spaces) are linear blocking sets. As a consequence, we get that minimal blocking sets of PG(n, p 3), p ? 7 prime, of size less than 3(p 3(n?k) + 1)/2 with respect to k-spaces are linear. We also give a classification of small linear blocking sets of PG(n, q 3) which meet every (n ? 2)-space in 1 modulo q points.