  The Fermi gamma-ray Space Telescope (Fermi) has detected hard X-ray (HXR) and
gamma-ray photons from three flares, which according to \stereo occurred in
active regions behind the limb of the Sun as delineated by near Earth
instruments. For two of these flares \r has provided HXR images with sources
located just above the limb, presumably from the loop top (LT) region of a
relatively large loop. Fermi-Gamma-ray Burst Monitor has detected HXRs and
gamma-rays, and RSTN has detected microwaves emissions with similar light
curves. This paper presents a quantitative analysis of these multi-wavelength
observations assuming that HXRs and microwaves are produced by electrons
accelerated at the LT source, with emphasize on the importance of the proper
treatment of escape of the particles from the acceleration-source region and
the trans-relativistic nature of the analysis. The observed spectra are used to
determine the magnetic field and relativistic electron spectra. It is found
that a simple power-law in momentum (with cut off above a few 100 MeV) agrees
with all observations, but in energy space a broken power law spectrum
(steepening at rest mass energy) may be required. It is also shown that the
production of the $>100$ MeV photons detected by The Fermi-Large Area Telescope
at the LT source would require more energy compared to photospheric emission.
These energies are smaller than that required for electrons, so that the
possibility that all the emissions originate in the LT cannot be ruled out on
energetic grounds. However, the differences in the light curves and emission
centroids of HXRs and $>100$ MeV gamma-rays favour a different source for the
latter.
