The UN Human Rights Council on Friday decided to send a group of experts to the Democratic Republic of Congo to help investigate an explosion of deadly violence in the Kasai region.
A council resolution called on the UN rights office to dispatch a team of international experts to help Kinshasa investigate gross rights violations in the region, including extrajudicial killings, torture, rape and the use of child soldiers.
More than 3,300 people have been killed in eight months of spiralling unrest in the central Kasai region, the papal envoy to the country said earlier this week.
About 1.3 million people have fled their homes, according to UN figures.
The resolution adopted by the 47-member council fell short of a call from the UN rights chief Zeid Ra'ad Al Hussein for a fully-fledged "independent, international investigation" following "horrific attacks" in the region.
The European Union, supported by the United States and others, had initially presented a draft resolution urging such an international probe.
But faced with harsh opposition from Kinshasa the western countries opted for a compromise, withdrawing their resolution and joining one presented by Tunisia on behalf of a group of African countries.
That text calls for the team of international experts, including ones from the region, "to collect and preserve information to determine the facts and circumstances... in cooperation with the (DRC) government".
The experts must forward their conclusions to the DRC authorities, the resolution says, stressing that "the perpetrators of deplorable crimes are all accountable to the judicial authorities of the Democratic Republic of the Congo".
It calls on Zeid to present a comprehensive report on the team's findings in the council's main annual session in March next year.
Tunisian representative Walid Doudech told the council the final text had been subject to "intense negotiations" and thanked the EU for enabling the "crucial compromise".
A Western diplomat close to the negotiations said the EU had preferred finding a compromise to pushing through an investigation sure to be boycotted by Kinshasa.
The negotiations "were not easy. But it was better to find a balanced solution with the participation of the country," the diplomat told AFP on condition of anonymity.
DRC ambassador Zenon Mukongo Ngay told the council his government would "accommodate the investigative team on its soil," but stressed the experts would only provide "technical and logistic support" and that "the Congolese judiciary will maintain the leadership in the investigation".
The violence in the Kasai provinces erupted in September when security forces moved in against followers of a tribal chieftain Kamwina Nsapu -- who had been killed a month earlier -- rebelling against the increasing authority of the central government.
Earlier this week, Zeid accused Congolese authorities of creating and arming a militia that has carried out "horrific attacks" on civilians, including mutilating babies and toddlers and slicing open pregnant women.
He also accused the Kamwina Nsapu rebels of committing serious abuses, including targeted killings and using child soldiers as young as seven.