相关规则
Luxembourg
Practice Relating to Rule 158. Prosecution of War Crimes
Luxembourg’s Law on the Repression of War Crimes (1947) provides for the prosecution and sentencing of non-Luxembourg nationals having committed war crimes
if such infringements have been committed at the occasion or under the pretext of war and if they are not justified by the laws and customs of war, these agents either being found within the Grand-Duché or on enemy territory, or the Government having obtained their extradition. 
Luxembourg, Law on the Repression of War Crimes, 1947, Article 1.
Luxembourg’s Law on the Punishment of Grave Breaches (1985) provides for the prosecution and punishment of persons having committed or being involved in the commission of grave breaches of the 1949 Geneva Conventions. 
Luxembourg, Law on the Punishment of Grave Breaches, 1985, Articles 1–8.
The Law also provides: “Any individual who has committed an offence under this law outside the territory of the Grand-Duché can be prosecuted in the Grand-Duché even though he may not be present there.” 
Luxembourg, Law on the Punishment of Grave Breaches, 1985, Article 10.