assumed to be dominated by emission from a relativistic jet pointing close to our line of sight. The jets in blazars consist of ultra-relativistic particles embedded in a magnetic field, with the entire plasma flowing outward from the central region with relativistic speed. The characteristic SED of blazars shows two broad non-thermal well defined continuum peaks. The first hump peaks somewhere between the infrared (IR) and X–ray bands, whereas the second hump exhibits a maximum at $\gamma$–ray energies. The origin of low energy peak is attributed to the synchrotron emission of relativistic electrons in the magnetic field of the jet. In leptonic models [@LM92; @CD93; @MS94; @MB00], the $\gamma$–ray emission in High Energy (HE: E$>$100 MeV) and Very High Energy (VHE: E$>$100 GeV) regimes is attributed to the inverse Compton (IC) scattering of low energy photons by the same electron population producing the synchrotron radiation (SSC: Synchrotron Self Compton) or with the possible contribution from external photons (EC: External Compton). In hadronic models [@MB92; @Ah00; @MP01; @MU03], both electrons and protons are accelerated to ultra-relativistic energies, with protons exceeding the threshold for photo-pion production on the soft photon field in the jet. In these models, the HE and VHE $\gamma$–ray 