De acordo com o site da Belarusian Airlines:
Is the transit visa needed?
According to the information, obtained from National airport Minsk border guard service:
Those passengers, who travel in transit through Minsk, do not need the Belarusian transit visa, if the following conditions are fulfilled:
- passengers have a valid passport and valid documents (national passport and/or visa , etc.) required for entry into the country of destination;
valid single ticket for the entire route to the destination point;
stay in Minsk does not exceed 24 hours and the passenger does not leave the so-called airport transit zone.
A Timatic confirma isso também:
Então a resposta é: no , você não precisa de visto de trânsito.