The risk of genocide in Sudan's devastating civil war remains "very high", amid alleged ethnically motivated attacks by the paramilitary Rapid Support Forces, the UN warned on Monday.

Since April 2023, Sudan has been torn apart by a power struggle between army chief Abdel Fattah al-Burhan and RSF commander Mohamed Hamdan Dagalo.

"The risk of genocide, war crimes and crimes against humanity in Sudan remains very high," said Acting Special Advisor on the Prevention of Genocide, Virginia Gamba.

The fighting has killed tens of thousands and displaced 13 million, including four million who fled abroad, triggering what the United Nations has called the world's worst humanitarian crisis.

"Both parties have committed serious human rights violations," said Gamba who is also a UN under-secretary.

"Of specific concern to my mandate is the continued and targeted attacks against certain ethnic groups, particularly in the Darfur and Kordofan regions," she told the UN Human Rights Council in Geneva.

She added in particular that the RSF and allied armed Arab militias "continue to conduct ethnically motivated attacks against the Zaghawa, Masalit and Fur groups".