A United Nations report into a decade of atrocities in the Democratic Republic of Congo says genocide may have been committed.
It found that tens of thousands of people were killed and many more raped, mutilated or victimised between 1993 and 2003.
As well as listing the involvement of Congolese groups, the UN document evokes military operations by other states including Rwanda.
“The crimes are very serious,” said UN High Commissioner for Human Rights Navi Pillay.
“Of course it is not a judgment; it is a collection of evidence and it may point to the commission of crimes such as war crimes because the laws of war forbid the killing of civilians. It points to crimes against humanity and in some instances may well amount to genocide.”
Only after a visit from UN Secretary General Ban Ki-moon last month did President Paul Kagame withdraw a threat to pull troops out of peacekeeping missions in protest at Rwanda being implicated.
At the centre of the report are crimes against Hutus who fled Rwanda amid fears of reprisals after the 1994 genocide.