Related Rule
United Kingdom of Great Britain and Northern Ireland
Practice Relating to Rule 115. Disposal of the Dead
Section B. Respect for the religious beliefs of the dead
The UK Military Manual (1958) provides: “The belligerents must make provision for … interment … if possible according to the rites of the religion to which the dead belong.” 
United Kingdom, The Law of War on Land being Part III of the Manual of Military Law, The War Office, HMSO, 1958, § 383.
The UK LOAC Manual (2004) states:
The remains of the dead are to be honourably interred (unless burial at sea is appropriate), in so far as possible in individual graves, and, if possible, according to the rites of the religion to which the deceased belonged. 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, § 7.35.
In 2003, in a written reply to a question in the House of Lords, the UK Parliamentary Under-Secretary of State, Ministry of Defence, stated:
The Deployed Operating Instructions issued to all United Kingdom military units state that enemy dead are to be treated the same as UK military dead. This includes a direction that, where next of kin cannot be traced, the bodies are to be given the same funeral as would UK military personnel, subject to religious practices. 
United Kingdom, House of Lords, Written answer by the Parliamentary Under-Secretary of State for Defence, Hansard, 8 September 2003, Vol. 652, Written Answers, col. WA40.