NAIROBI — A report from the United Nations' office for human rights said Friday that killings and rapes committed by ethnic militias in Congo's northeastern Ituri province from 2017 to 2019 may amount to crimes against humanity and even genocide.

The attacks displaced hundreds of thousands of people, many of whom remain in refu­gee camps within Ituri, as well as in neighboring Uganda. They were carried out largely by members of the Lendu community against the Hema, a larger but politically weaker group.

The Congolese military and local police did not do enough to stem the violence, the report added.

Allegations of such an extreme nature are rare, since both crimes against humanity and genocide have stringent definitions, but the fact that the United Nations created those definitions lends credibility to the accusations.

“The barbarity that characterises these attacks — including the beheading of women and children with machetes, the dismemberment and removal of body parts of the victims as trophies of war — reflects the desire of the attackers to inflict lasting trauma to the Hema communities and to force them to flee and not return to their villages,” the report said.

At least 701 people have been killed and 168 wounded, and an additional 142 were victims of sexual violence, according to the report. Almost all the victims were Hema, but the report did mention cases of Hema retaliatory attacks that killed and wounded Lendus.

The Lendu and the Hema have a long history of violence that dates back to the Belgian colonization of Congo. Lendu leaders claim that Belgian administrators favored the Hema, giving them access to jobs and land while depriving other communities. The latest bout of violence is the fourth major instance.

In April 2018, The Washington Post documented the dismal conditions many Hema faced in makeshift refu­gee settlements in Uganda, which they reached by harrowing journeys through thick forest and across a large lake on boats whose owners extorted them.

The International Criminal Court sentenced former Congolese military leader Bosco Ntaganda, who belongs to the Hema community, last November to 30 years in prison for atrocities including murder, rape and conscripting child soldiers for battles mostly targeting the Lendu.