ยง 2. Crimes
Section 5
2. Anyone who commits, in the case of an international armed conflict, one of the grave breaches of the Additional Protocol (I), concluded in Bern on 12 December 1977, to the Geneva Conventions of 12 August 1949, relating to the protection of victims of international armed conflicts (Netherlands Treaty Series 1980, 87), namely:
(c) the following acts, when they are committed intentionally and in violation of the relevant provisions of Additional Protocol (I) and cause death or serious injury to body or health:
(v) making a person the object of attack in the knowledge that he is hors de combat; or
Killing or wounding a combatant who has laid down his arms and surrendered at discretion - IAC
Killing or wounding a combatant who no longer has means of defence and has surrendered at discretion - IAC
EDIT.