GRBs an nowadays a rather well understood phenomenon in the soft (KeV-MeV)
gamma-ray energy band, while only a few GRBs have been observed at high pho
ton energies (E gamma greater than or similar to 1 GeV). It is also widely
recognized that GRBs accelerate protons to relativistic energies and that d
ense media are often present nearby the sources. Within this framework and
by further adopting Totani's suggestion that GRB events release an amount o
f energy similar to 10(54) Delta Omega erg, we compute in detail the high-e
nergy gamma-ray flux from the decay of neutral pious produced through the i
nteraction of accelerate protons with nucleons in the surrounding medium. W
e also take into account the local and intergalactic gamma-ray absorption.
The presence of magnetic fields around the GRB sources causes the deflectio
n of the accelerated protons and so a temporal spread of the produced high-
energy gamma-rays with respect to the signal in the soft gamma-ray band. Mo
reover, we analyze the possibility to detect the gamma-ray signal in the Ge
V-TeV energy range by the ARGO detector under construction in Tibet.