Army troops in the Democratic Republic of Congo shot and beat to death about 50 Rwandans in April and burnt their refugee camp, a UN investigator says.
Philip Alston said about 40 women were also abducted and it prompted a revenge massacre by Rwandan Hutu militia.
His report said military operations this year carried out by the army supported by UN peacekeepers in the east had produced catastrophic results.
They have been pursuing Hutu rebels who have been based in DR Congo for years.
The BBC’s Thomas Fessy in the capital, Kinshasa, says Mr Alston gave horrifying details of his investigation.
He said the attack on the makeshift refugee camp of Shalio in North Kivu happened on 27 April.
The government troops involved were the newly integrated rebels from the Tutsi-led movement which threatened to take over the provincial capital Goma a year ago.
At least 96 civilians were massacred in a neighbouring village by Rwandan-Hutu militia in revenge for the Shalio killings.
In his report, the UN expert said the UN Security Council had transformed the peacekeeping force into a party to the conflict.
SOURCED FROM BBC