Related Rule
United Kingdom of Great Britain and Northern Ireland
Practice Relating to Rule 129. The Act of Displacement
Section C. Ethnic cleansing
The UK LOAC Manual (2004) states in its chapter on internal armed conflict:
Recent armed conflicts have been blighted by the use of “human shields” to protect military installations from attack and by the practice known as “ethnic cleansing” when people of a certain racial origin or religious beliefs have been murdered or expelled from their homes, which have been destroyed. These practices violate the basic law of armed conflict principles of targeting, discrimination and humane treatment of those hors de combat as well as the basic human rights law principles of non-discrimination on racial or ethnic grounds and in freedom of thought, conscience, and religion. They are likely to be war crimes. Depending on the circumstances, these practices may also amount to crimes against humanity or even genocide. 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, § 15.14.2.
In 1992, during a debate in the UN General Assembly, the United Kingdom declared that “ethnic cleansing” in the former Yugoslavia was “inhuman and illegal”. It added: “We reject as inhuman and illegal any expulsion of civilian communities from their homes in order to alter the ethnic character of the area.” 
United Kingdom, Statement before the UN General Assembly, UN Doc. A/46/PV.89, 24 August 1992, p. 36.
In 1994, during a debate in the UN Security Council on the situation in Bosnia and Herzegovina, the United Kingdom stated that it was undeniable that “the abhorrent practice of ‘ethnic cleansing’ … is a crime, and a most grievous one”. 
United Kingdom, Statement before the UN Security Council, UN Doc. S/PV.3428, 23 September 1994, pp. 32–33.