A/HRC/18/40 45. Hundreds of civilians, including women and children, were killed in fighting between the SPLA and rebel militia groups. Since the referendum in January 2011, UNMIS has documented massive human rights violations committed in the context of this fighting. The violence can be traced to events following the April 2010 elections, when several former SPLA generals fell out with the movement over allegations of vote-rigging, formed militia groups and launched armed rebellions against the SPLA. While a majority of the casualties were soldiers on both sides, a substantial number of civilians has been targeted and killed on suspicion of being affiliated with rebel militia groups. The SPLA and other militia groups have committed human rights abuses, including the deliberate burning of villages and indiscriminate killing of civilians, including women and children, looting and rape and sexual violence against women. Between January and April 2011, UNMIS reported that more than 1,000 people, including hundreds of civilians, were killed in the fighting concentrated in the Greater Upper Nile region of Jonglei, Upper Nile and Unity State. Tens of thousands of civilians have been forced to flee their villages and many of them remain inaccessible to humanitarian actors. 46. Systematic human rights abuses continue in an environment of impunity, with the most frequent and worst abuses perpetrated by the security forces of Southern Sudan. There have been numerous reports of human rights abuses by the SPLA, including extrajudicial killings, arbitrary arrests, detentions and cases of sexual and gender-based violence. During the referendum, most of the human rights violations documented by UNMIS involved the SPLA. Like the SPLA, the Southern Sudanese Police Service (SSPS) commits serious human rights violations in its law enforcement operations. The SSPS remains ill-trained and under-equipped, and consists of many former militia and ex SPLA members, many of whom are illiterate and unqualified. In January 2011, an UNMIS investigation into the operations of the only training centre for police in Southern Sudan, at Rajaf, near Juba, uncovered allegations of serious human rights violations, including cases of extrajudicial killing, torture, rape and inhumane and degrading treatment meted out to trainees. The investigation also revealed a culture of training practices reflecting the guerrilla force 17