According to RT.com:
13:13 GMT
The passengers who were sitting near the back of the plane died of so-called “explosive trauma,” sustaining 90 percent skin burns and having metal pieces in their bodies, Russian tabloid LifeNews reports, citing the results of a forensic examination. Those closer to the front of the plane died of different types of injuries, including blood loss, open cranio-cerebral traumas and multiple fractures. So far, there has been no official response to these reports.