10:44, Moscow time
Siberia Airlines official statement
According to updated information from Head of the Military Sector of the Main Center of the Russian Unified System of Air Traffic Control, the hijacking alarm which was received last night came from the TU-154 plane of Siberia Airlines. It happened just before the loss of contact with the plane and its disappearance from the radar screens.
As it has been reported, last night the air company's Flight Control Center received a telegram with information about the alarm sent from one of the missing planes and a request for additional security measures.
More airline's official statements (in English) on the
Sibir website