Ok., for the English speaking community: According to BFU`s official statement mentioned above, FDR data proves that the crew, after an ice detection alert upon reaching FL 100, had indeed switched on engine anti-ice and air frame anti-ice. 6 minutes later engine vibrations became noticeable and increased considerably, 4 minutes later engine power became insufficient and an emergency landing was initiated. Broken ice impact trays were later found in both engines, causes to be further investigated.
(edited for spelling)