More than 170 bodies have been found in two neighborhoods near the city of Uvira in South Kivu, the province's governor has said

At least 171 bodies have been discovered in mass graves in eastern Democratic Republic of the Congo (DR Congo), in an area recently held by M23 rebels, the Associated Press reported on Thursday, citing a local official. The reports come as violence escalates in the African state despite ceasefire efforts.

The graves were found near the city of Uvira in South Kivu province, Governor Jean-Jacques Purusi said. He relayed that 30 bodies had been discovered in Kiromoni, near the border with Burundi, and 141 others in Kavimvira.

The governor and the Local Network for the Protection of Civilians, a civil society group in the region, accused M23 fighters of killing civilians suspected of supporting the Congolese army or allied militias.

In December, the rebels seized Uvira on Lake Tanganyika before the Congolese army retook the city last month. Kinshasa said more than 1,500 people were killed in the offensive. The UN says about 200,000 people have fled the fighting, including more than 30,000 who crossed into neighboring Burundi.

The discovery comes days after M23 military spokesman Willy Ngoma was killed in a drone strike reportedly carried out by the Congolese army in neighboring North Kivu.

READ MORE: Rebel spokesperson killed in DR Congo - media

Mass graves have been uncovered repeatedly in the troubled Central African country. In 2023, UN investigators found sites containing dozens of civilians in Ituri province. Last July, Human Rights Watch said M23 had summarily executed more than 140 in villages near Virunga National Park, accusing the group of widespread abuses.

The UN says the conflict in eastern Congo has created one of the world's worst humanitarian crises, displacing millions.

In a statement on Thursday, issued on the sidelines of a UN Human Rights Council meeting in Geneva, United Nations experts reported that M23 fighters had used "extreme" violence against defenders of human rights in North and South Kivu.

"We are horrified by the gravity and brutality of the abuse committed against human rights defenders and their families," the experts said.