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.

Rwanda-backed rebels claimed they captured eastern Congo’s strategic city of Goma, the hub of a region containing trillions of dollars in mineral wealth that remains largely untapped, the Associated Press reported.

United Nations Secretary-General Antonio Guterres on Tuesday spoke separately with the presidents of the Democratic Republic of Congo and Rwanda about the escalating conflict in eastern Congo, U.N. spokesperson Stephane Dujarric said.

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.

Rwanda-backed M23 rebels faced pockets of resistance from army and pro-government militia overnight after entering eastern Congo's largest city Goma in the worst escalation of a conflict that has run for more than a decade.

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.

Rwanda-backed rebels claimed on Monday they captured eastern Congo’s strategic city of Goma, the hub of a region containing trillions of dollars in mineral wealth that remains largely untapped.

Rwanda-backed rebels claimed they captured eastern Congo’s strategic city of Goma, the hub of a region containing trillions of dollars in mineral wealth that remains largely untapped, the Associated Press reported.

The Rwandan-backed M23 rebels now have full control of Goma's airport and the border with Rwanda. Civilians who fled the rebels must now contend with life under their rule.

Congo's security forces are fighting against Rwanda-backed rebels who advanced into a key eastern city in a major escalation of a decadeslong conflict.

Rebels claim to have captured the key city of Goma in the DRC, as the decades-long conflict becomes even more volatile. Sky News takes a look at what's going on.