Ukraine’s defence intelligence service said on Thursday that a Russian Su-30 fighter jet had been successfully shot down with a portable anti-aircraft system during a special operation in the Black Sea. The jet was shot down on Wednesday and belonged to a Russian Air Force regiment based out of the occupied Crimean peninsula, a statement said. There was initially no mention in Moscow of the loss of an aircraft. However, the Russian military blog Rybar, which is close to the Defence Ministry in Moscow, reported that an Su-30 had been shot down. The Defence Ministry said on Wednesday that Ukrain…