SAKE: Thousands of civilians poured out of the town of Sake in the eastern DR Congo on Friday in the face of a rebel advance that has raised fears of wider conflict erupting in the chronically unstable region.

An AFP photographer saw at least one body in the center of the town, a day after it fell to the rebels, while the head of a relief agency reported numerous casualties.

“There are bodies lining the road” leading south from Sake, Thierry Goffeau, the head of the Goma chapter of Doctors Without Borders (MSF) told AFP, without providing specific figures.

The M23 rebels earlier in the week captured Goma, a regional capital in the mineral-rich Kivu region, where the two wars that shook the country beginning in 1996 started.

The rebels' lighting advance has displaced tens of thousands of people and has raised warnings of a looming humanitarian catastrophe in an area with little infrastructure.

On Friday, thousands of residents fled Sake on foot, a day after rebels captured the town. They headed east toward Goma some 30 kilometres away and where tens of thousands of people are estimated to already be sheltering in camps.

A UN source said that the army and an allied local militia had managed to stop the rebel advance some 10 kilometres south of Sake, but this information could not be independently confirmed.

The M23 rebels have been blamed for hundreds of deaths since the former army soldiers mutinied in April, unhappy with the outcome of a 2009 peace deal that integrated them into the regular army.

One of their leaders is Bosco Ntaganda, a former army general nicknamed the “Terminator” who is wanted by the International Criminal Court on charges of war crimes and crimes against humanity.

The UN has accused neighbouring Rwanda and Uganda of backing the rebels, charges that both countries deny.

The North and South Kivu regions are the easternmost of DR Congo, sub-Saharan Africa's largest country, and have a history of unrest.

The region is rich in cobalt, copper, diamonds, gold and coltan, a key component of mobile phones.

Two wars shook the country between 1996 and 1997 and then again from 1998 to 2002 both beginning in the Kivu region, with Rwanda and Uganda playing active or behind-the-scenes roles in much of the fighting.

Since 1998 more than three million people are estimated to have died from combat, disease and hunger and 1.6 million have been left homeless.

The former Belgian colony, known as Zaire under the dictator Mobutu Sese Seko, who was toppled in 1997, remains one of the world's least developed countries despite its mineral wealth.