The bodies of at least 87 people allegedly killed by the Rapid Support Forces (RSF) in Sudan have been found in a mass grave, according to the UN.
The organisation said Masalit people were among those buried in a shallow grave just outside El-Geneina.
Fierce fighting between the RSF and Sudan’s armed forces has been continuing since April.
But the RSF and their allied militias have denied any involvement in the recent fighting in West Darfur.
Thousands have died and millions have been forced from their homes as a result of fighting between Sudan’s regular army, led by Abdel Fattah al-Burhan, and the RSF, led by al-Burhan’s former deputy, Mohamed Hamdan Daglo, known as “Hemedti”.
The UN said at least 37 bodies were buried in the West Darfur region on 20 June, and another 50 at the same site the next day. Among those buried were women and children.
UN High Commissioner for Human Rights Volker Türk said he was “appalled by the callous and disrespectful way the dead, along with their families and communities, were treated”.
He called for an investigation into their deaths and said the RSF was obliged to treat the dead “with dignity”.
Earlier this week, the RSF rejected allegations from Human Rights Watch that they had killed 28 members of the Masalit community and injured dozens of civilians before destroying the town of Misterei in May.
An adviser to the RSF leadership, Mustafa Mohamed Ibrahim, told the BBC the clashes there were part of an ongoing civil war between Arab groups and the Masalit “which is old and renewed”.
Last month, the West Darfur governor was killed shortly after he accused the RSF of carrying out a genocide against the Masalit people.
The Masalit people once lived under a sultanate in West Darfur, most of which was incorporated into Sudan more than 100 years ago.
They are predominately Muslims and have accused successive Sudanese governments of promoting “Arabism” – overlooking them for basic services such as education and health.
There are concerns that attacks by the RSF and Arab militias against the Masalit community could result in a repeat of the 2003 Darfur killings, when 300,000 people were killed by the Janjaweed militias, who later grew into the RSF.
The UN has already received reports of Arab militia targeting Masalit men and said the conflict has taken on an “ethnic dimension”.