It seems that announced success of launching Kanopus-ST military satellite seemed to be premature.
Mission of Kanopus-ST was started at 5 December 2015 (post about launch is here) and seemed that will be success. Unfortunately Kosmos-2511 lost contact with ground control and it seemed that became space debris. It was announced that satellite failed to separate with Volga module – one of four locks failed to open. It is not known if additional satellite, Kosmos-2512 (KYuA-1) is operational, but due the fact that it was placed on the side of Volga upper stage, it is possible that this separation was correct.
Reenter window expired at 05:08 UTC. According to TASS, satellite burned in atmosphere over southern Atlantic.
Kanopus-ST attached to Volga should be visible in central Mexico, USA and Canada from 0:30 UTC, just like on the map below:
According to USSTRATCOM Kanopus-ST will reentry probably on 06:54 UTC 8th December 2015. It is possible that spacecraft with Volga module will not burn completely in atmosphere and fragments will reach Earth surface. It is confirmed that KYuA-1 was separeted correctly from Vega.