Соответствующая норма
Practice Relating to Rule 63. Use of Flags or Military Emblems, Insignia or Uniforms of Neutral or Other States Not Party to the Conflict
Belarus’s Criminal Code (1999) provides that it is a war crime to “use intentionally, during hostilities, in violation of international treaties, … the national flag or distinctive signs … of a neutral State”. 
Belarus, Criminal Code, 1999, Article 138.