Sudanese refugees who have fled from the war in Sudan line up during a cash assistance programme at a Transit Centre for refugees in Renk, on February 15, 2024. [AFP]

Authorities in Sudan have received more than 550 reports of rape committed by paramilitary fighters since war began in April 2023, an official with the army-aligned government told AFP on Tuesday.

The information shared by Sulaima Ishaq al-Khalifa, head of a government unit to combat violence against women, comes as the United States earlier on Tuesday accused the paramilitary Rapid Support Forces (RSF) of "rape and other forms of brutal sexual violence" throughout the war.

A UN mission has also found evidence of "widespread sexual and gender-based violence".

Khalifa told AFP that her agency had documented 554 cases of rape by RSF fighters between April 2023 and December 2024.

The figure is based on reports from mental health professionals who assisted rape survivors at medical facilities, and so likely represents a tiny fraction of the actual number of attacks on women over that period, said Khalifa.

"Some regions are completely isolated, communications have been disrupted and many women avoid reporting sexual violence due to the fear of social stigma," she said.

For more than 20 months, Sudan has been locked in a bloody power struggle between army chief Abdel Fattah al-Burhan and his former deputy, RSF leader Mohamed Hamdan Daglo.

The war has killed tens of thousands, uprooted 12 million and created what the United Nations describes as one of the worst humanitarian disasters in recent memory.

Khalifa said that between September 2023 and April 2024, authorities had approved 36 abortions for women raped by paramilitaries, most of them in the capital Khartoum.

More recently, 10 abortions have been performed for women displaced from Al-Jazira state, where civilians reported a series of brutal attacks by the RSF.

In Sudan, abortions require legal approval and are permitted in cases of rape, non-viable pregnancies or life-threatening complications.

On Tuesday, US Secretary of State Antony Blinken said the RSF had "committed genocide" in Sudan, accusing the paramilitary of atrocities including "deliberately (targeting) women and girls from certain ethnic groups for rape and other forms of brutal sexual violence".

In October, the United Nations Independent International Fact-Finding Mission for Sudan accused the RSF and its allied militias of "widespread sexual and gender-based violence" including "rape, sexual slavery" and other abuses.

The mission has also documented cases of gender-based violence committed by the army and allied groups.

But the UN probe determined that the RSF was behind systematic "sexual violence on a large scale".

The RSF, which did not respond to an AFP request for comment on the figures shared by the government officials, has previously dismissed the findings of the UN mission as "propaganda".