  Analysing mid--infrared ISOCAM images of the cluster of galaxies J1888.16CL,
we identified among its members several particularly active galaxies with total
infrared luminosities well above 10^{11} Lsun. If powered by dust enshrouded
starbursts, as suggested by their optical spectra, these Luminous Infrared
Galaxies would exhibit star formation rates surprisingly high in the cluster
environment. The triggering mechanism is unclear but could be tidal collisions
within sub-structures or infalling groups.
