Nairobi, Goma  - It is a story that is as old as it is depressing: a rebel group more concerned with filling its pockets than the welfare of the people it says it is defending.

The rumbling conflict in the east of the Democratic Republic of Congo, which blew up into full-scale fighting for four days last week, conforms to this pattern.

Rebel Tutsi general Laurent Nkunda, who last week routed the Congolese army and sent tens of thousands of civilians fleeing in terror, says he is fighting to defend Tutsis from armed Hutu militia.

These Hutu militia fled to Congo after the 1994 massacre in Rwanda, when Hutu militants killed an estimated 800,000 Tutsis and moderate Hutus in the space of a few months.

But the real prize is the deposits of gold, tin, diamonds and coltan or columbite-tantalite - used widely in mobile phones - in the sprawling Central African nation.

"It is all about control of the minerals," said Muzong Kodi, Associate Fellow at the Africa Programme of London-based think tank Chatham House. "You have the smokescreen of ethnic problems, which do exist, but they are being manipulated."

Almost 80 per cent of the world's coltan supplies are found in DR Congo. The deposits of coltan and other resources are believed to be worth hundreds of billions of dollars.

Nkunda says he won't stop fighting the Hutu Democratic Forces for the Liberation of Rwanda (FDLR) until they leave the DR Congo, but with such riches available the FDLR is not going anywhere.

According to independent watchdog Global Witness, the FDLR and the Congolese army are in cahoots in the mining trade.

"Local residents told us that the FARDC (Armed Forces of the Democratic Republic of Congo) are doing exactly the same thing as the FDLR: taking over the mines, forcing civilians to work for them or to hand over their mineral production and extorting taxes," Global Witness Director Patrick Alley said.

Nkunda's National Congress for the Defence of the People (CNDP) is also involved in mining and is doing very well from it.

"Nkunda is making a lot of money smuggling minerals over the border to Rwanda, taxing people and seizing money from individuals," said Kodi. "He is not going to stop."

All of the groups funnel the minerals they mine through middlemen. Much of it ends up on the Asian markets for use in electronic products.

Global Witness puts part of the blame for the conflict on companies that do not check the source of the minerals they buy.

"As long as there are buyers who are willing to trade, directly or indirectly, with groups responsible for grave human rights abuses, there is no incentive for these groups to lay down their arms," said Alley.

The knowledge that conflict in DR Congo is about profit is hardly a revelation. The 1998-2003 war that engulfed the nation and drew in many of its neighbours was widely viewed as a resource grab.

More than 5 million people are estimated to have died as a result of the 1998-2003 war, most of them from hunger and disease.

However, dialogue and peace deals, including the deal the CNDP signed up to in January this year and then broke in late August, focus on the political aspect.

"The underlying criminalized economy setup has never been discussed," said Kodi.

The latests flare-up caught the world's attention as tens of thousands of desperate civilians streamed away from the rebel advance.

Now a United Nations aid convoy is taking advantage of a ceasefire to deliver medical supplies to those caught behind rebel lines and diplomatic activities are in full swing.

Western diplomats, including the British and French foreign ministers, scrambled to set up meetings with Rwandan President Paul Kagame and DR Congo President Joseph Kabila.

Kagame and Kabila agreed to a regional meeting, with UN Secretary General Ban Ki-moon saying he will attend, but the resource issue is unlikely to be on the table.

Ultimately, the response from the international community has been far from robust.

Alan Doss, the head of the UN peacekeeping mission in the DR Congo (MONUC) has admitted his 17,000-strong force is struggling to cope. Yet calls for more troops have so far not been answered with any firm commitments.

According to Kodi, this weak response means that Nkunda is likely to carry on with his campaign, bringing more misery to those refugees foraging for berries in the woods and hoping for food aid to come.

"Nkunda is trying the waters," Kodi said. "When he first pulled out of the agreements two months ago, there was no strong reaction. His first move was to attack."

"Diplomats will spend months speaking to each other, Nkunda will move forward and we will see chaos far worse than we have seen so far," he added. (dpa)