24 INTERNATIONAL LEGAL PROTECTION OF HUMAN RIGHTS IN ARMED CONFLICT or non-State armed groups.24 It is also recognized that rules of customary international law related to non-international armed conflicts, such as the principles of distinction and proportionality, are applicable to nonState armed groups. As mentioned above, those customary rules tend to become increasingly similar in international and in non-international armed conflicts. Concerning international human rights obligations, the traditional approach has been to consider that only States are bound by them. However, in evolving practice in the Security Council and in the reports of some special rapporteurs, it is increasingly considered that under certain circumstances non-State actors can also be bound by international human rights law and can assume, voluntarily or not, obligations to respect, protect and fulfil human rights. For instance, the Security Council has called in a number of resolutions on States and non-State armed groups to abide by international humanitarian law and international human rights obligations.25 The Special Rapporteur on extrajudicial, summary or arbitrary executions indicated in the context of his mission to Sri Lanka that “[a]s a non-State actor, the LTTE does not have legal obligations under [the International Covenant on Civil and Political Rights], but it remains subject to the demand of the international community, first expressed in the Universal Declaration of Human Rights, that every organ of society respect It should be noted that the threshold for the applicability of Protocol II to non-State armed groups is sensibly higher than that of common article 3. Article 1 of Protocol II indicates that its provisions apply to organized armed groups which, under responsible command, exercise such control over a part of a State’s territory as to enable them to carry out sustained and concerted military operations and to implement the Protocol. Article 3, on the other hand, does not contain any such condition and instead indicates that its provisions apply as minimum standards to parties to a non-international armed conflict. 25    See, for example, resolution 1894 (2009), in which the Security Council, while recognizing that States bear the primary responsibility to respect and ensure the human rights of their citizens, as well as all individuals within their territory as provided for by relevant international law, reaffirms that parties to armed conflict bear the primary responsibility to take all feasible steps to ensure the protection of civilians, and demands that parties to armed conflict comply strictly with the obligations applicable to them under international humanitarian, human rights and refugee law. 24