After three years on the run from the Rwandan-backed M23 insurgency in eastern Congo, on Sunday, with the rebels fighting their way into Goma's city outskirts, Colleta Nzambonimpa found herself in church with nowhere left to turn.

The UN and global powers fear the conflict could spiral into a regional war akin to those of 1996-1997 and 1998-2003 that killed millions.

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 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.

Rebels led by the M23 group claim to have taken control of Goma, a key city in the eastern Democratic Republic of the Congo.

At least 17 people have been killed in clashes between M23 rebels backed by Rwanda and forces loyal to the Democratic Republic of Congo's government in the eastern city of Goma, hospital sources

After three years on the run from the Rwandan-backed M23 insurgency in eastern Congo, on Sunday, with the rebels fighting their way into Goma's city outskirts, Colleta Nzambonimpa found herself in church with nowhere left to turn.

A lightning advance in Congo's mineral-rich eastern borderlands is set to boost the M23 rebellion's illegal mining revenues, with analysts predicting a further surge in illicit trade in minerals including coltan and gold through neighbouring Rwanda.

The M23 rebels are one of about 100 armed groups vying for a foothold in the mineral-rich region in the conflict, one of Africa’s largest.