  We study spectra of the Ultra High Energy Cosmic Rays assuming primaries are
protons and photons, and that their sources are extragalactic. We assume power
low for the injection spectra and take into account the influence of cosmic
microwave, infrared, optical and radio backgrounds as well as extragalactic
magnetic fields on propagation of primaries. Our additional free parameters are
the maximum energy of injected particles and the distance to the nearest
source. We find a parameter range where the Greisen-Zatsepin-Kuzmin cut-off is
avoided.
