Human Rights Watch says the Sudanese Armed Forces and the Rapid Support Forces and affiliated fighters have summarily executed, tortured, and ill-treated people in their custody, and mutilated dead bodies.
It says leaders of both forces should privately and publicly order an immediate halt to these abuses and carry out effective investigations.
The organisation says they should cooperate fully with international investigators, notably from the UN Independent International Fact-Finding Mission for Sudan, who should include these abuses, which constitute war crimes, within the scope of their investigations.
Channel Africa's Nhlanhla Mahlangu spoke to Horn of Africa director at Human Rights Watch Laetitia Bader.