We investigate production of φ mesons and Ξ baryons in nucleusnucleus collisions.Reactions on strange particles acting as a catalyser are proposed to interpret the high observed φ yields in HADES experiments as well as the energy dependence of the widths of φ rapidity spectra in collisions at the SPS energies.It is argued that the enhancement of Ξ -yield observed by HADES is even higher than originally reported, if effects of the experimental centrality trigger are taken into account.Cross sections for new hadronic processes that could produce Ξ -are reviewed.