If confirmed, the attack would be the latest in a string of dozens of attacks by RSF soldiers on small villages across the farming state after it took control of the capital Wad Madani in December.
A telecommunications blackout prevented Reuters immediately reaching medics or residents to verify the death toll.
“Wad Alnoura village … witnessed a genocide on Wednesday after the RSF attacked twice, killing up to 100 people,” the pro-democracy Wad Madani Resistance Committee said in a statement on social media late on Wednesday.
Later it put the number of dead in the hundreds, and said the Sudanese army had not heeded a request for help.
The RSF began fighting the army in April 2023 after disputes over the integration of the two forces, and has since taken over the capital Khartoum and most of western Sudan.
It is now seeking to advance into the centre, as United Nations agencies say the people of Sudan are at “imminent risk of famine”.
In a statement on Wednesday, the RSF said it had attacked army and allied militia bases around Wad Alnoura but did not acknowledge any civilian casualties.
But the Wad Madani Resistance Committee accused it of using heavy artillery against civilians, looting, and driving women and children to seek refuge in the nearby town of Managil.
It shared photos of dozens of bodies wrapped for burial in an open square among large crowds of men.
“The people of Wad Alnoura called on the army to rescue them, but they shamefully did not respond,” the committee said. The army-aligned Transitional Sovereign Council condemned the attack.
“These are criminal acts that reflect the systematic behaviour of these militias in targeting civilians,” it said in a statement.
The international community has recently warned of a looming offensive on El-Fasher, the last major city in Darfur that is not under control of the paramilitary Rapid Support Forces (RSF).
Guterres is “alarmed by reports of the use of heavy weaponry in densely populated areas, resulting in dozens of civilian casualties, significant displacement and the destruction of civilian infrastructure,” Farhan Haq, a spokesman for the secretary-general, said in a statement.
The UN chief is particularly concerned for civilians in the area who “are already facing a looming famine and the consequences of over a year of war,” Haq added.
He repeated Guterres’s call for an immediate ceasefire and for all parties to allow civilians to move to safer areas and facilitate unimpeded humanitarian access.
Since April 2023 Sudan has been gripped by a devastating war between the army, headed by the country’s de facto leader Abdel Fattah al-Burhan, and the paramilitary RSF, commanded by his former deputy Mohamed Hamdan Daglo.
Fighting broke out on Friday and ran into the weekend with air strikes in the north and east of El-Fasher, as well as artillery fire, according to residents interviewed by AFP.
On Friday alone, clashes between the army and RSF left at least 27 people dead and 130 injured, the United Nations said.
