Related Rule
Botswana
Practice Relating to Rule 89. Violence to Life
Botswana’s Geneva Conventions Act (1970) punishes “any person, whatever his nationality, who, whether in or outside Botswana, commits, or aids, abets or procures the commission by any other person of, any such grave breach of any of the [1949 Geneva] conventions”. 
Botswana, Geneva Conventions Act, 1970, Section 3(1).
In 1995, during a debate in the UN Security Council on the situation in the former Yugoslavia, Botswana stated that if the information relative to the execution of captives were confirmed, these acts would constitute the most blatant and flagrant violations of IHL and accepted norms of international morality. 
Botswana, Statement before the UN Security Council, UN Doc. S/PV.3591, 9 November 1995, p. 5.