Local residents have said that M23 rebels forced them to dig mass graves to bury the victims.
France said on Thursday it was "horrified" by a recent massacre in the Democratic Republic of Congo that left at least 131 people dead and called on "all armed groups to stop fighting immediately and engage in the disarmament process without delay".
A preliminary report from the UN released Thursday found that DR Congo's M23 rebel group was responsible for the massacre, and of committing rape and looting at the end of November, in two villages in eastern DRC in retaliation for clashes with armed groups.
Authorities in Kinshasa said the death toll is much higher, claiming around 300 people were killed in the village of Kishishe in North Kivu province.
The UN preliminary investigation, based on eyewitness accounts concerns Kishishe and the nearby village of Bambo.
It states that 102 men, 17 women and 12 children were killed "during acts of reprisal against the civilian population".
"The victims were arbitrarily executed by bullets or with bladed weapons," Monusco -- the UN peacekeeping mission in DR Congo -- said in a statement.
"Eight people were also wounded by bullets and 60 others abducted. At least 22 women and five girls were raped.
"The violence was committed as part of a campaign of murder, rape, abduction and looting against these two villages in Rutshuru territory in retaliation for clashes between the M23 and FDLR (Forces Démocratiques de Libération du Rwanda) militiamen and other armed groups", the statement said.
The investigation was conducted by the UN Joint Human Rights Office and Monusco, which "interviewed 52 victims and direct witnesses, and various sources" in Rwindi, a town 20 km from Kishishe, where a Monusco base is located and where victims and witnesses have taken refuge.
The investigators were unable to go to Kishishe and Bambo "because of security constraints due to the fact that Kishishe is currently controlled by the M23 and the high risk of reprisals against the victims and witnesses still present in the area", Monusco said.
The M23 has denied having committed this massacre, acknowledging only the death of 8 civilians killed by "stray bullets" during clashes in Kishishe between its fighters and militiamen.
Local residents report mass graves
Local residents in Kishishe told reporters by telephone that M23 rebels ordered them to bury the victims in mass graves.
In its statement, Monusco said, according to the preliminary investigation team, that "elements of the M23 would have buried the bodies of the victims themselves, in what could be an attempt to destroy the evidence".
M23 -- March 23 Movement -- is a former Tutsi-dominated rebellion that took up arms again in late 2021 and in recent months has conquered large swathes of territory north of Goma, the provincial capital of North Kivu.
According to Congolese authorities, UN experts and US diplomats, the M23 is supported by Rwanda. But Kigali disputes this, accusing Kinshasa, which also denies it, of collusion with the FDLR, an essentially Hutu movement formed by some of the perpetrators of the 1994 Tutsi genocide in Rwanda.
Among the various diplomatic initiatives launched to try to resolve the crisis in eastern DRC, a summit held on 23 November in Luanda decided on a ceasefire on the evening of 25 November, followed two days later by a withdrawal of the M23 from conquered areas.
An East African regional force being deployed in North Kivu could potentially intervene to dislodge the rebel fighters.
M23 said this week it was "ready to start disengaging and withdrawing", but no withdrawal has been observed so far.