Great Uncle photos around WWI, which army?

[grogger]

Here are two photos of my grandmother's brother Mykolas (1895 - 1980). He was Lithuanian. In the photo with the four men he is in the back on the left. A friend of mine said the man in the darker uniform was an officer and that the four must have been together for a long time becuase he is allowing one to touch him and pour him a drink. Any idea what army they maybe from?

[Henrik Andersson]

Russian army.
I belive his cap is russian and is belt to!