Just by looking at the maps, I don't think that there is an airside connection between the arrival an departure level. That said, the terminal is fairly small.

Maybe there's on VNO expert, but I tend to say that you would have to exit through the baggage claim area, go to the upper level, walk back by walking past the check-in desks, go through security and immigration (given that Minsk is not within Schengen).

http://www.vilnius-airport.lt/en/tip...king-services/