Human Rights Watch accused M23 rebels and the Rwandan Defence Force of carrying out killings, rapes and enforced disappearances during a month-long occupation of the eastern Congolese city of Uvira in late 2025 and early 2026.
In a report released Thursday, the rights group said M23 fighters committed widespread abuses after briefly capturing the city in December before withdrawing weeks later under pressure from the United States.
Human Rights Watch documented at least 53 summary executions, eight rapes and 12 enforced disappearances during the occupation, accusing the rebels of targeting civilians suspected of links to pro-government militias.
According to the report, fighters opened fire on civilians attempting to flee the city and carried out door-to-door searches targeting men and boys allegedly connected to local armed groups aligned with the Congolese government.
Neither the Rwandan government nor an M23 spokesperson immediately responded to the allegations.
Both Rwanda and the rebel group have repeatedly denied accusations of human rights abuses in eastern Congo and have instead accused the Congolese army and allied militias of targeting members of the Tutsi community.
The conflict in eastern Democratic Republic of the Congo has continued despite mediation efforts involving regional and international actors, including the United States.
In March, Washington imposed sanctions on the Rwandan Defence Force and senior military officials over allegations that Rwanda was backing M23 operations in eastern Congo, claims Kigali has denied.
The report comes days after M23 fighters reportedly withdrew from several positions in South Kivu province, retreating around 30 kilometers north of Uvira.