Air — Hijacking — Conviction under municipal legislation — Sri Lanka Offences Against Aircraft Act 1982 — Statute enacted to fulfil international obligations — Convention on Offences and Certain Other Acts Committed on Board Aircraft, 1963 — Convention for the Suppression of Unlawful Seizure of Aircraft, 1970 — Convention for the Suppression of Unlawful Acts Against the Safety of Civil Aviation, 1971 — Whether conviction under statute enacted after offences committed lawful — Whether permissible for domestic legislation to have retroactive effect where offence already recognized as a crime by the community of nations

Jurisdiction — Nationality principle — Whether courts of State of nationality have jurisdiction over offences committed outside that State on board foreign aircraft — The law of Sri Lanka