Advances being made by the M23 rebel group in the Democratic Republic of Congo are "heightening the threat of a regional war," according to U.N. Secretary General Antonio Guterres.

Angolan President Joao Lourenco has urged warring parties in the Democratic Republic of Congo (DRC) to return to peace talks, which collapsed last year, the foreign ministry said.

North Kivu is a province bordering Lake Kivu in the eastern Democratic Republic of the Congo. The capital city is Goma.

The United Nations Security Council on Sunday demanded that M23 rebel forces stop an ongoing offensive and advance towards Goma, the largest city in eastern Democratic Republic of Congo, and that "external forces" in the region immediately withdraw.

GOMA, Democratic Republic of Congo (Reuters) -Congolese rebels said on Sunday they had taken Goma, the biggest city in the east of the mineral-rich country, after a lightning advance that has forced thousands of people to flee and fuelled concerns of a regional war.

An African country that's the 11th largest in the world also shares its border with a staggering nine other countries.

The violence in eastern Congo has escalated. Near Goma in North Kivu, 13 peacekeepers were killed by M23 rebels, while Congo has broken off relations with Rwanda. The North Kivu region is rich in gold and coltan.

Civilians in eastern Democratic Republic of Congo are at increasing risk as the abusive M23 armed group, supported by the Rwanda Defence Force (RDF), approaches Goma, the capital of North Kivu province.

The former US administration has said the government of Rwandan President Paul Kagame rebuffed a proposed peace incentive for a deal between Congo and

Congo has severed diplomatic ties with Rwanda as fighting between Rwanda-backed rebels and government forces rages around the key eastern city of Goma.

Admiring the courage of Blue Helmets, Ambassador Akram urged MONUSCO, the UN peacekeeping force in DR Congo, and the UN to take immediate measures to ensure the safety and security of the civilians and that of the UN and other peacekeeping units in eastern DR Congo.

Angolan President Joao Lourenco has urged warring parties in the Democratic Republic of Congo (DRC) to return to peace talks, which collapsed last year, the foreign ministry said.