Rwandan-backed rebels moved to tighten their grip on the strategic city of Goma in the east of the Democratic Republic of Congo on Monday in what Kinshasa described as “a declaration of war” by its neighbour.

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.

M23 fighters have been pressing to capture strategic eastern city for months and intensified offensives in recent days.

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

M23 rebels claim they now control the Congolese city of Goma—an act Congo's government described as a 'declaration of war.'

M23 rebels in the Democratic Republic of Congo were reported to have taken the key eastern city of Goma in fierce fighting with government forces that sent streams of refugees fleeing area communities.

South Africa's Permanent Representative to the United Nations, Ambassador Mathu Joyini, has stated that South Africa will continue to contribute to promoting peace and stability in the eastern region of the Democratic Republic of Congo and to the continent's overall peacekeeping efforts.

Residents in eastern Congo’s largest city of Goma are fleeing after Rwanda-backed rebels claimed to have captured the regional hub from Congolese forces.

The M23 militia, funded and directed by Rwanda, said it had seized the city of Goma, terrifying its people, many of whom sought shelter there after fleeing the rebel advance.

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

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.