According to the media, don Cossack and a former soldier of the airborne troops went there as a volunteer and fell into the hands of militants in Deir-ez-Zor at the end of September or earlier.

Some sources speaks of them as Russian troops, but Moscow has repeatedly said that Russian soldiers in Syria did not get captured.

Last week two Russian Deputy said, citing its sources that the prisoners are likely to have already killed for refusing to join the ranks of the "Islamic state".

In the Kremlin, in turn, said that the Russian security services now to find out how all of the above information is true.