Nearly 3,000 people were killed over the last week as rebels captured a key city in one of the deadliest battles in the Central African country in decades.

The Democratic Republic of Congo will present a motion to the United Nations Human Rights Council seeking an investigation into what it called "mass violations" of rights in the city of Goma, its envoy told reporters on Thursday.

The U.N.’s top human rights body has condemned Rwanda’s support of rebel fighters across the border in eastern Congo and ordered a team of experts to examine rights violations in the region

Worse violence "may be yet to come" in the conflict-hit Democratic Republic of Congo, UN High Commissioner for Human Rights Volker Türk said on Friday. An offensive by the Rwanda-backed M23 rebel group against Congolese forces in and around the eastern city of Goma has left almost 3,