The United Nations has opened an investigation into killings in central Democratic Republic of Congo , though some Western countries and campaign groups say they had hoped it would have a stronger mandate.
Congo's government has been fighting armed groups in the Kasai region since August, prompting fears of a wider conflict in the central African country, riven by ethnic rivalry and competing claims over mineral resources.
Congo's Catholic Church said this week the violence had killed more than 3,300 people since October, with both government forces and the militia responsible for hundreds of deaths.
On Friday, the UN's Human Rights Council (UNHRC), composed of 47 member states, adopted by consensus the resolution calling for an investigation, brought by African countries.
Zenon Mukongo Ngay, Congo's ambassador, addressing the inter-governmental body, said President
Joseph Kabila 's government would cooperate to shed light on atrocities.
But the Congolese justice system would be in charge of the joint investigations, with the UN providing "technical or logistical support", he said.
Zeid Ra'ad Al Hussein, the UN high commissioner for human rights, who is to name fact-finding experts to the investigation, had called repeatedly for an international inquiry into the events in Kasai, an opposition stronghold.
"We fully support the establishment of an international investigation ... as a step forward in identifying the perpetrators of gross violations and bringing them to justice," Zeid said in a statement.
His office, the OHCHR, is counting on the "full cooperation" of the government and on the experts having unfettered access to all sites, files, people and places.
"The team will conduct investigations in a fully independent manner, in accordance with international standards," he said.
Zeid told the UNHRC on Tuesday that a militia linked to the government has committed a string of ethnically motivated attacks in recent months, including cutting off toddlers' limbs and stabbing pregnant women.
The Congolese government has repeatedly denied that security forces systematically use excessive force and insists it is capable of conducting its own investigations.
Several government officials have said in recent days that they were pleased an EU proposal for a fully independent international investigation into the violence had been withdrawn.
However, diplomats said elements of that had been incorporated into the African text.
In a statement to the UNHRC, Jason Mack, a representative from the US delegation, said the United States welcomed the resolution but retained doubts about the Congolese government's commitment to a transparent investigation.
Paul Nsapu, deputy secretary-general of the International Federation for Human Rights (FIDH), a French nongovernmental organisation, said investigators might not have sufficient authority to identify perpetrators of rights abuses.
"This resolution risks not being enough to stop the massacres," he said.
Leila Matar of Human Rights Watch said in a statement that the inquiry "brings hope of uncovering the truth about the horrific violence".