Report from Interfax, citing Russian defense ministry
They also report that the helicopter hit by a Turkmen rebel group was 1 of 2 helicopters on the rescue mission for the pilots. They've confirmed the one of the pilots was killed.
The helicopter story is an interesting one by itself. It was reportedly hit by a TOW missile but that was after it was already on the ground (perhaps with mechanical trouble). The missiles have been provided to Syrian rebels by the United States.
Congress funding weapons for Syrians to shoot a Russian helicopters isn't a pretty picture.
The same group also reportedly executed the two Russian pilots.