  Cosmic rays accelerated to ultra-high energies (E>4x10^19 eV) in electric
fields in accretion discs around supermassive black holes are discussed.
Particle injection spectra are assumed to be harder than those formed in
acceleration on shock fronts. It turned out that cosmic rays with injection
spectra supposed contribute a little in the particle flux detected with
ground-based arrays. But in the extragalactic space particle generate a
noticeable flux of the diffuse gamma-ray emission compared with the data
obtained with the Fermi LAT instrument (onboard the Fermi space observatory).
The intensity of neutrinos generated by cosmic rays propagating in the
extragalactic space is also derived. The model intensity of cascade neutrinos
is much lower than that of astrophysics ones. It is concluded that possibly
supermassive black holes are cosmic ray sources which contribute slightly to
the particle flux detected on the Earth, but these sources should be taken into
account when analyzing components of extragalactic diffuse gamma-ray emission.
