Multijets in Photoproduction and Minijets in DIS at HERA

Two measurements based on electron-proton collision data collected at HERA are presented. From the ZEUS collaboration measurements are presented on 3- and 4-jet cross sections in photoproduction. H1 collaboration is for the first time dedicating an analysis to search for multiple interactions in DIS. Both analyses show results which are pointing out the relevance of contributions from the underlying event.