  We report an extensive numerical study of a charged colloidal system with
competing short-range depletion attraction and long-range electrostatic
repulsion. By analizing the cluster properties, we identify two distinct
regions in the phase diagram: a state composed of stable finite-size clusters,
whose relative interactions are dominated by long-range repulsion, and a
percolating network. Both states are found to dynamically arrest at low
temperatures, providing evidence of the existence of two distinct non-ergodic
states in these systems: a Wigner glass of clusters and a gel.
