The United Nations named three human rights experts on Wednesday to lead an international investigation into killings and other crimes in the Kasai region of Democratic Republic of Congo, a move that risks a showdown with the government.
Congo has insisted that its own justice system is in charge of the inquiry with the United Nations providing "technical or logistical support". Some Western states and campaign groups said they had hoped for a stronger U.N. mandate.
The announcement came a day after the U.N. Joint Human Rights Office in Congo (UNJHRO) accused "elements" of the Congolese army of digging most of dozens of mass graves discovered in recent months in Kasai.
Bacre Waly Ndiaye, a U.N. investigator from Senegal, will lead a fact-finding team that includes Luc Cote, a Canadian who worked on a previous U.N. inquiry into Congo atrocities, and Mauritania's Fatimata M'Baye.
They were named by the U.N. High Commissioner for Human Rights, who has called for perpetrators to be prosecuted, including the pro-government Bana Mura militia that he said had cut off childrens' limbs and sliced open pregnant women.
Government spokesman Lambert Mende played down any differences over the investigators' mandate as "semantic" and said the Kinshasa government had instructed its embassies to help the experts procure visas.
But he sharply criticized the U.N.'s findings from Tuesday on the mass graves. "Before the investigators arrive, they have already designated the guilty," Mende said.
More than 3,000 people have been killed and 1.4 million displaced in the violence, part of a wave of unrest that has worsened since President Joseph Kabila refused to step down when his mandate expired in December.
The U.N. Human Rights Council's resolution launching the inquiry last month cited reports of "recruitment and use of child soldiers, sexual and gender-based violence, destruction of houses, schools, places of worship and state infrastructure by local militias, as well as of mass graves".
Kinshasa has been fighting insurgents in the Kasai region since August and there are fears of a wider conflict in the vast central African country, a tinderbox of ethnic rivalry and competing claims over mineral resources.