A rebel alliance claimed the capture of the biggest city in the Democratic Republic of Congo’s mineral-rich eastern region this week, pushing back against resistance from government troops backed by regional and UN intervention forces.

U.S. Secretary of State Marco Rubio called for a urgent cease-fire in the conflict in eastern Democratic Republic of Congo saying Washington was "deeply troubled" by a recent escalation in the fighting.

South African President Cyril Ramaphosa accuses Rwanda of backing M23 rebels behind escalating crisis in eastern Democratic Republic of Congo this week

Authorities say the governor of eastern Congo’s North Kivu province has died from injuries sustained in fighting on the front line as M23 rebels close in on Goma.

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.

Rwanda-backed rebels who have captured eastern Congo’s largest city say they plan to take their rebellion to the capital and seek to gain political power.

Rwanda, which diplomats say backs M23 fighters who seized Goma in Democratic Republic of Congo this week, called on Wednesday for a ceasefire across eastern Congo and for Congo to negotiate with the rebels while denying Rwandan troops were involved.

M23 rebels, with support from Rwandan troops, marched into Goma earlier this week and are now advancing south toward Bukavu.

Kenyan President William Ruto, who chairs the East African Community, announced that he had convened an Extraordinary Summit mid-week to discuss the security crisis in the eastern Democratic Republic of Congo (DRC).

Reuters quoted the spokesperson as saying that the UN is deeply concerned by these developments, which are backed by "credible reports."

The Rwandan-backed M23 group is advancing further south in DR Congo, local and humanitarian sources told AFP Thursday, after the group vowed it would march to the capital Kinshasa.