Congolese President Félix Tshisekedi has vowed to restore government authority in the east, where Rwanda-backed M23 rebels have seized control of the city of Goma and are reportedly advancing south to take more territory.

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 scene is the result of the invasion of Goma on January 27th by M23, an armed group under the control of Rwanda, Congo’s neighbour, which abuts the city. Paul Kagame, Rwanda’s president, has escalated a crisis whose origins go back decades.

A conflict that has raged for decades reached a flashpoint this week when rebels backed by Rwanda marched on a key Congolese city in a bid to occupy territory and exploit minerals.

M23 rebels have made rapid advances in the latest bout of conflict that has long-dogged the mineral-rich east.

The weeks-long march of the M23 armed group, which has captured vast swathes of eastern DRC including most of the key city of Goma, has prompted calls for crisis talks and warnings of a looming humanitarian crisis.

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.

Angola's president called Wednesday for the "immediate withdrawal" of Rwandan troops from the Democratic Republic of Congo and for leaders of both countries to meet in Luanda urgently over the conflict.

The latest fighting has heightened an already dire humanitarian crisis in the region, forcing half a million people from their homes since the start of the year.

Angola's president called Wednesday for the "immediate withdrawal" of Rwandan troops from the Democratic Republic of Congo

The Rwanda-backed armed group M23 vowed on Thursday to march on the DR Congo capital, Kinshasa, as its fighters made further advances in the mineral-rich east of the country.