A/HRC/30/61 to have surrendered to the Sri Lankan military. Although some facts remain to be established, on the basis of witness testimony as well as photographic and video imagery, there appears to be sufficient information in several cases to indicate that they were killed after being taken into custody. Depending on the circumstances and if confirmed by a court of law, many of the cases described in the report may amount to war crimes and/ or crimes against humanity. B. Violations relating to the deprivation of liberty 28. The investigation team documented long-standing patterns of arbitrary arrest and detention by government security forces, and of abductions by paramilitary organizations linked to them, which often reportedly led to enforced disappearances and extrajudicial killings. 29. The typical modus operandi involved the arbitrary arrest or abduction of individuals by the security forces, sometimes with the assistance of paramilitary group members operating in unmarked “white vans” that were reportedly able to pass security checkpoints or to enter security force bases. 30. These violations were and still are facilitated by the extensive powers of arrest and detention provided for in the Prevention of Terrorism Act still in force, and by the emergency regulations that were in force until 2011. Such cases of unlawful and arbitrary arrest and detention are clearly in violation of the State’s obligations under international human rights law. Depending on the circumstances and if confirmed by a court of law, these violations may amount to war crimes and/or crimes against humanity. C. Enforced disappearances 31. During the course of its investigation, the team reviewed reliable information on hundreds of cases of enforced disappearance arising during the period under review in various parts of the country, with particular prevalence in the Northern and Eastern Provinces. Furthermore, the mass detention regime after the end of hostilities also led to enforced disappearances. 32. On the basis of the information available, the team has reasonable grounds to believe that the Sri Lankan authorities have, in a widespread and systematic manner, deprived a considerable number of victims of their liberty, and then refused to acknowledge the deprivation of liberty or concealed the fate and whereabouts of the disappeared person. This, in effect, removed these persons from the protection of the law and placed them at serious risk. Family members of the disappeared persons were also subjected to reprisals and denied the right to an effective remedy, including the right to the truth. 33. There are reasonable grounds to believe that enforced disappearances may have been committed as part of a widespread and systematic attack against the civilian population, given the geographical scope and time frame in which they were perpetrated, by the same security forces and targeting the same population. In particular, there are reasonable grounds to believe that those who disappeared after handing themselves over to the army at the end of the conflict were deliberately targeted because they were or were perceived to be affiliated with LTTE forces. 7