At least 40 people have been killed in an attack on a camp for displaced people in Sudan's western Darfur region, according to an aid group that works there.

The Abu Shouk Emergency Response Room said Monday's assault was carried out by the Rapid Support Forces (RSF). The resistance committee in nearby el-Fasher city, made up of local citizens and activists, also reported this.

El-Fasher, which came under intense attack as well, is the last major foothold in Darfur for the army and its allies, which have been fighting the paramilitary RSF in the two-year civil war.

The conflict has triggered a humanitarian crisis with the UN warning that families trapped in the besieged city faced starvation.

Sudanese media reported that the camp was caught in the crossfire of the fighting in el-Fasher.

But the aid group inside Abu Shouk, where at least 200,000 people live, said some of those killed in the attack were shot in their homes while others were gunned down in public.

A US-based organisation that analyses satellite imagery and videos said that it identified a large grouping of 40 light vehicles in the north-west neighbourhoods of the camp, which appear to corroborate reports that the attack came from the north.

The Yale Humanitarian Research Lab added that it was investigating images and videos "allegedly showing RSF shooting at people crawling away from them and berating and using ethnic slurs".

The camp was created more than two decades ago by people from non-Arab communities - including the Fur and Zaghawa - who were fleeing attacks by the Janjaweed militia.

The RSF has its origins in this notorious militia that was accused of carrying out a genocide.

The paramilitary group has also been widely accused of ethnic cleansing in Darfur during this war, and the US has sanctioned it with allegations of genocide.

The RSF has previously denied such charges, saying it is not part of what it calls tribal conflicts.

Zaghawa fighters have joined the army in defending el-Fasher, so it is possible that the RSF was deliberately targeting Zaghawa civilians in the camp.

The camps for displaced people near el-Fasher have frequently come under attack during the war.

In April, more than 100 people died and thousands fled Zamzam camp as the RSF occupied it and took it over.

Since the conflict began in April 2023, tens of thousands of people have died, 12 million have been forced from their homes and famine has been declared in parts of the country.