tidal field experienced by the member galaxies during a cluster-cluster interaction, probably being close to the core passage. Studying a system of merging clusters, @JHS08 observed an excess of star-forming galaxies aligned along the bridge of galaxies connecting A3158 to the A3125/A3128 complex, suggestive of merger-induced SF. In addition, they found that the fraction of radio-loud sources is lower with respect to a global cluster environment and similar to that measured by @VBM00 in the cluster A3558 which is considered as an example of a late merger stage. They suggested that in the cluster cores radio emission from active galactic nuclei (AGNs) is suppressed in the late stages of cluster mergers. The suppressed radio emission observed in both bright and faint cluster galaxies has been also associated to cluster merger by @MM07. They explained their findings with the disruption of cool cores, i.e. the gas supply to the central AGN for the bright galaxies, while the low radio loudness and fainter cluster galaxies have been affected by the enhanced ram pressure when crossing the shock front between the merging clusters. Further observational support of the important role that cluster mergers play in triggering the evolution of cluster galaxies is provided 