Dark sector searches in final states with prompt neutral particles with the ATLAS detector.

The possibility that Dark Matter constitutes a new sector of particles with a new interaction is investigated by the ATLAS experiment at LHC. Searches often look for single dark photon (DP) jets reconstructed from exotic decays of the Higgs boson into dark particles, which shower into a pair of DPs that decay back into pairs of collimated leptons or light hadrons. I will report recent results on final states with at least two reconstructed DP jets, which allow to probe wider areas of the free model parameter space under the hypothesis that the DP decays promptly into SM particles.