Rwanda-backed rebels said on Monday they captured Goma in eastern Congo, the government’s last stronghold in the mineral-rich region.

It marks a sharp escalation in the one of Africa’s longest wars, threating to dramatically worsen an already dire humanitarian crisis and spill into a wider regional conflict.

The rebels’ offensive has sent thousands fleeing their homes, in addition to one million displaced who are already in Goma, and stretched local hospitals to the limit, with hundreds of wounded coming in every day as civilians get caught in the crossfire.

Here is what to know about the conflict:

Who are the rebels and what do they want?
The M23 group is one of about 100 armed factions vying for a foothold in the mineral-rich region in a decades-long conflict in eastern Congo. The group, made up primarily of ethnic Tutsi, led a defeated insurgency against the Congolese government in 2012. It was then dormant for a decade, until its resurgence in 2022.

In recent weeks, the rebels have made significant territorial gains, seizing towns and villages and encircling Goma.

The group traces its origins to the failed integration of ethnic Tutsis who broke away from the Congolese army. In 1994, Hutu militias in neighboring Rwanda killed between 500,000 and one million ethnic Tutsi, as well as moderate Hutus and Twa, an indigenous people. Following the genocide, many Hutus fled to eastern Congo.

M23 claims to defend ethnic Tutsi and Congolese of Rwandan origin from discrimination. Critics say it’s a pretext for Rwanda to obtain economic and political influence over eastern Congo.

In territories under its control, M23 implements its own tax system, controls natural resources and implements a parallel governance system, replacing traditional chiefs with their people.

M23 refers to the March 23, 2009, agreement that ended a previous uprising in the region.

What’s the role of neighboring Rwanda?
Congo, the United States and U.N. experts accuse Rwanda of backing the M23, which had only hundreds of members in 2021. Now, according to the United Nations, the group has around 6,500 fighters.

While Rwanda denies that claim, it acknowledged last year that it has troops and missile systems in eastern Congo, allegedly to safeguard its security. U.N. experts estimate there are up to 4,000 Rwandan forces in Congo.

Analysts say that Rwandan troops present in eastern Congo have been increasingly active in recent weeks.

Congo’s foreign minister, Thérèse Kayikwamba Wagner, told a session of the U.N. Security Council on Sunday that Rwanda was committing “a frontal aggression, a declaration of war which no longer hides itself behind diplomatic maneuvers.”

Rwanda’s ambassador to the U.N., Ernest Rwamucyo, did not confirm or deny Congo’s claims. He blamed Congo’s government, saying the crisis could have been been averted if it had “demonstrated a genuine commitment to peace.”

What are the reasons behind the fighting?
Eastern Congo, abundant in metals and rare earth minerals such as copper, cobalt, lithium and gold, has been a theater of violence for decade.

Most of the country’s mineral resources remain untapped and are estimated to be worth $24 trillion, according to the U.S. Department of Commerce last year, which called Congo the world’s leading producer of cobalt, key to making batteries.

Little of the region’s wealth has trickled down to Congolese citizens, with 60% out of its 100 million residents living below poverty line. Instead, it has attracted a variety of armed groups and external actors who sought control over its valuable natural resources.

Between 1996 and 2003, the region found itself at the heart of a protracted conflict dubbed “Africa’s world war,” which killed up to 6 million people.

The conflict first broke out after the 1994 genocide in the neighboring Rwanda, when nearly 2 million Hutu refugees crossed into Congo, mostly settling in North and South Kivu provinces. Rwandan authorities said that many of them participated in the genocide and were protected by elements of Congolese army.

A small fraction of Hutu set up militias inside Congo, which was met by a violent response from the Tutsi community. Tensions between Hutu and Tutsi in Congo exacerbated, and served as a justification for foreign powers to get involved.

At the time, Kigali argued that Hutu militias were still a threat to Rwanda’s Tutsi population — the same argument it makes today.

Over the years, as the world has relied more than ever on Congo’s metals and rare earth minerals to produce electronics, the stakes for local and external players got even higher. Congo’s neighbors Rwanda and Uganda have financial interests in Congolese mines, as well as China and the United States.

Why is Goma important for the rebels?
The city is a regional hub for trade, security and humanitarian efforts, and its airport is key for transporting supplies.

Since 2021, Congo’s government and allied forces, including Burundian troops and U.N. troops, have been keeping the rebels away from Goma.

The capture of such a large city will certainly be a huge boost for the rebels and a major defeat of the government forces.

Its fall would also have a “catastrophic impact on hundreds of thousands of civilians, putting them at risk of heightened exposure to human rights violations and abuses,” said Ravina Shamdasani of the U.N. human rights office.

Is this likely to resolve like the last time?
Back in 2012, the rebels seized Goma and controlled it for about a week but after mounting international pressure on Rwanda — including suspension of aid from the United States and Britain — the M23 surrendered the city.

But analysts say this time around, it is going to be more difficult.

“Previously, they (M23) had clear demands to be integrated into the DRC army and have greater participation in the political process,” said Darren Davids, an analyst with the Economist Intelligence Unit. But now, he said, “it seems like M23, with the help of Rwanda are intent on holding control of Goma, and more specifically, the supply chain routes in North Kivu.”

The rebels’ strategy is more likely to use Goma as a bargaining chip, strengthening their position in possible negotiations with Congo.

What is the situation of the civilians?
There are 4 million displaced people in eastern Congo. The U.N. refugee agency says more than 400,000 people have been displaced since the beginning of the year, exacerbating “desperate conditions” in severely overcrowded displacement centers in and around Goma and triggering an increase in cholera cases.

As rebels closed in on Goma over the many more fled from surrounding villages and displacement camps into the city. Others fled from Goma into Rwanda.

Staff at Goma’s main hospital were sheltering in a bunker, treating the wounded while coming under gunfire and heavy artillery fire.

(AP)