  Ultra High Energy (UHE) particles coming from discrete extragalactic sources
are potential candidates for EAS events above a few tens of EeV. In particular,
galaxies with huge infrared luminosity triggered by collision and merging
processes are possible sites of UHECR acceleration. Using the PSCz catalogue of
IR galaxies we calculate a large scale anisotropy of UHE protons originating in
the population of the luminous infrared galaxies (LIRGs). Small angle particle
scattering in weak irregular extragalactic magnetic fields as well as
deflection by regular Galactic field are taken into account. We give analytical
formulae for deflection angles with included energy losses on cosmic microwave
background (CMB). The hypotheses of the anisotropic and isotropic distributions
of the experimental data above 40 EeV from AGASA are checked, using various
statistical tests. We show that on the basis of the small scale clustering
analysis there is a much better correlation of the UHECRs data below GZK
cut-off with the predictions of the LIRG origin than with those of isotropy. We
derive analytical formulae for a probability of a given number of doublets,
triplets and quadruplets for any density distribution of independent events on
the sky. The famous AGASA UHE triple event is found to be very well correlated
on the sky with the brightest extragalactic infrared source within 70 Mpc -
merger galaxies Arp 299 (NGC 3690 + IC 694).
