Tagged photons produced by the ROKK-2 facility have been used to measure the photofission cross section of in the energy range 60 - 270 MeV. Fission events were detected by using a nuclear fragment detector based on multiwire spark counters. Fissility values have been deduced and compared with available data obtained with monochromatic photons in other laboratories. These data have been analysed in the framework of a two-step model which considers the primary photointeraction occurring via the quasi-deuteron and/or photomesonic processes, followed by a mechanism of evaporation - fission competition for the excited residual nucleus. The model was found to reproduce the main experimental features of photofissility up to 300 MeV.