Well unless there are more of those pics, there surely isen't any indication that these guys shold be PLA troops. Both guys are wearing maskes and gogles which make the assumption of them being "asian" impossible. In the other pic there isen't showing any heads at all. Also there is nothing in the enviroment cpatured in these pictures, only water which looks like it could be one of your lakes if all we know. More logical awnser is ofcourse in some Russian lake...
But if there is more of these pictures that reveals more, could you post them as well?