We present a possible explanation for the existence, in colloidal systems, of low-density disordered arrested states contiguous to a cluster phase, providing evidence that the gel formation in short-ranged attractive colloidal systems can be formally connected to a cluster glass transition. Contrary to what has been proposed before, we suggest that the gel phase is not stabilized by the short range attraction but, instead, it is generated by the presence of a weak long-range screened electrostatic repulsive interaction. We provide evidence that the gel is essentially a Wigner glass, composed by clusters of colloidal particles, which allows us to formally describe the gel formation with the same physics of the glass formation.