Human Rights Watch (HRW) has published a damning report accusing the M23 militia of committing murder, rape and “other war crimes” in the volatile east of the Democratic Republic of the Congo in recent months.

In the report released on Tuesday, HRW said it had so far “documented eight unlawful killings and 14 cases of rape” by M23 fighters.

Last year, the United Nations accused the group of executing at least 131 people in November in retaliation for clashes between M23 and rival armed groups. The UN’s human rights office then later said that 171 civilians were executed in the last ten days of November.

In April and May, after the group withdrew from Kishishe, HRW used photos, videos, testimonies and satellite images to establish the presence of 14 mass graves in the village.

The group – whose members are predominantly ethnic Tutsis from Rwanda – has captured swathes of territory in DRC’s North Kivu province since taking up arms in late 2021 after years of dormancy, with over a million people displaced by the fighting.

The DRC accuses Rwanda of backing the M23. Independent UN experts and several Western nations, including the United States, agree with Kinshasa. But Kigali continues to deny the claims.

“The United Nations Security Council should add M23 leaders, as well as Rwandan officials who are assisting this abusive armed group, to the council’s existing sanctions list,” HRW said in a statement on Tuesday.

“The M23’s unrelenting killings and rapes are bolstered by the military support Rwandan commanders provide the rebel armed group,” said Clementine de Montjoye, Africa researcher at the New York-based rights monitor.

One of the survivors was a 46-year-old woman who was raped in February. “As they were raping me, one said: ‘We’ve come from Rwanda to destroy you’,” she said.

Her 75-year-old mother was shot dead for refusing to let the M23 fighters have sex with her.

Meanwhile, The M23 denied the allegations in a statement and accused the watchdog of seeking to tarnish its image.

Kigali has also dismissed HRW’s report.

“Rwanda is not going to be intimidated by these campaigns of disinformation and distractions from ongoing regional peace efforts,” government spokesperson Yolande Makolo told the AFP news agency.

The HRW report also claimed that groups backed by the DRC government in the fight with the M23 were also guilty of raping civilians.