A China Eastern Airbus A330-200, registration B-5926 performing flight MU-774 (Jun 17th) from Paris Charles de Gaulle (France) to Kunming (China), was enroute at FL390 about 260nm northeast of Tyumen (Russia) the aircraft encountered severe turbulence including two large jolts causing the aircraft to experience multiple rapid descends and climbs (in excess of 5000 fpm) reaching a minimum of FL349 as well as injuries to 26 people on board. The aircraft continued to Kunming for a safe landing about 5:45 hours later. Four passengers were taken to hospital with serious injuries (fractures and head injuries), 22 passeners with minor injuries.