The United Nations has revealed that M23 rebels killed at least 131 civilians in eastern Democratic Republic of the Congo late last month.
In a preliminary investigation into the November 29-30 massacres in the villages of Kishishe and Bambo, the UN peacekeeping mission, and the Joint Human Rights Office found the killings were undertaken in retaliation for clashes between M23 and rival armed groups.
Authorities in Kinshasa had earlier said more than 270 people were killed in the M23 attacks in North Kivu province.
It added that 102 men, 17 women and 12 children were killed by bullets or other weapons.