  We propose a model in which prompt gamma emission of gamma-ray bursts is the
synchrotron radiation of electron-positron plasma in the ordered magnetic field
in the direct vicinity of horizon of a young black hole formed in the core
collapse of a massive star. This mechanism can naturally explain high degree of
polarization of the gamma-ray flux and hard low energy photon spectral index.
Interaction of gamma-quanta with ambient matter provides a mechanism of
formation of relativistic ejecta which are responsible for the gamma-ray burst
afterglows.
