Congo has severed all diplomatic ties with Rwanda and South Africa said on Saturday that nine of its peacekeepers had been killed amid a surge in fighting with Rwanda-backed rebels in mineral-rich eastern Congo.

The resource-rich eastern provinces of North and South Kivu have been plagued by conflicts for three decades, with the Rwanda-backed M23 emerging as one of the most powerful armed groups in recent years.

Nine South African peacekeepers have been killed in clashes with M23 forces in the Democratic Republic of Congo, including two from UN peacekeeping force MONUSCO, the defence ministry said Saturday.

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.

The Democratic Republic of Congo has formally recalled its diplomats from Rwanda and demanded that Rwanda halts its diplomatic activities in the Congolese capital within 48 hours. The directive came through a letter verified by a foreign ministry official,

A spokesman for the Democratic Republic of Congo's army said Saturday: "Rwanda is determined to seize the city of Goma" in the east of the country.

On Sunday, January 26, an emergency meeting of the UN Security Council on the situation in the Democratic Republic of the Congo will be held, the newspaper Le Monde reports.

The M23 armed group has seized further territory in the east of the Democratic Republic of Congo and on Thursday was continuing to tighten its grip on provincial capital Goma, which is almost surrounded by fighting.

Congo has severed diplomatic ties with Rwanda amid intensifying M23 insurgency and ongoing battles. Allegations of Rwanda's involvement in the conflict have been denied by Rwanda, but tensions rose with the killing of a Congolese military governor.

A war is raging in eastern Congo. It involves the DRC's (Democratic Republic of the Congo) regular army and the M23 group, backed by the Rwandan army. Tensions have been rising for several days. Turkey offers to mediate.

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.