The M23 armed group has seized further territory in the east of the Democratic Republic of Congo and on Thursday was continuing to tighten its grip on provincial capital Goma, which is almost surrounded by fighting.
Weaknesses within the Congolese army, as well as backing from Rwanda are aiding the fighters of the M23, according to experts, who have not ruled out an offensive on Goma, at the heart of the mineral-rich region torn apart by 30 years of conflict.
M23 'puppets' of Rwanda
For several weeks, clashes between the M23 and Congolese armed forces (FARDC) have intensified.
Hospitals have seen an influx of patients, and since the beginning of January, more than 230,000 people have fled the violence, the United Nations said.
The army acknowledged on Tuesday a "breakthrough" by "the Rwandan army and its M23 puppets" after the capture of Minova, a trading town supplying Goma some 50 km from the city by road.
A UN expert report seen by AFP in July said that 3,000 to 4,000 Rwandan soldiers had been fighting alongside the M23 and that Rwanda had "de facto control" of the group's operations.
Kigali has never explicitly recognised territorial aggression in the DRC.
No obstacles towards Goma
M23 fighters early this month had already captured Masisi, the administrative capital of Masisi territory in North Kivu province which lies around 80 km northwest of Goma and has around 40,000 inhabitants.
The closest fighting to Goma is around 10 km away.
The armed group has occupied the hills around Goma for almost two years and threatens to choke the city's economy by taking the port of Minova in the west.
The FARDC and militias backing the army have established defensive lines around the city.
But observers doubt these forces could offer real resistance in the event of an offensive.
A UN peacekeeping force known as MONUSCO has a base in Goma, but it is unclear how it will react if the city falls.
In December, a meeting between Congolese President Felix Tshisekedi and Rwandan President Paul Kagame, as part of an Angola-led peace process, was cancelled due to lack of agreement.
At this stage, "nothing prevents the M23 and Rwanda from trying to take Goma," Reagan Miviri, a researcher at the Congolese Ebuteli institute, told AFP.
"The Luanda process is no longer there; the American pressure is no longer there. Rwanda has nothing to fear, it seems to accept this aggression," he said.
Some observers also fear Donald Trump's return to the White House might impact Rwandan attitudes. Kagame recently said he was "certain" that "many things, even on the geopolitical level, will change ... in particular those linked to the east of the DRC".
Weakness of the army
Eastern DRC has vast mining resources and is a complex landscape of rival armed militias which has seen violence ebb and flow since regional wars in the 1990s.
The M23 was formed in 2012 from a mutiny within the army of former fighters of the National Congress for the Defence of the People (CNPD), a Congolese political-military movement with a Tutsi majority that is now inactive.
It had already taken control of Goma by the end of November 2012.
But 11 days later, the Congolese army had retaken the city with the support of the UN mission in the DRC and diplomatic pressure from the international community on Rwanda.
At the end of 2013, the FARDC had driven the armed group out of the last positions it occupied in the mountains of North Kivu.
The M23 resurfaced at the end of 2021 and the Congolese army has rarely recovered territory lost in recent months.
"We have some symbolic towns where we're going to have the Congolese military allocating a significant number of resources ... being able to overwhelm the M23 at a very local level," Remi Dodd, sub-Saharan Africa analyst at RANE Network said.
But Dodd pointed to the challenges faced by the army, such as "corruption, inadequate equipment ... low morale and also low discipline".
"All of these challenges really impede the ability (of the FARDC) to respond to the M23," he said.
Meanwhile, the "inaction" of the troops of the Southern African Development Community (SADC) present in North Kivu is becoming "flagrant", according to other observers.
The forces deployed to support the FARDC are composed of soldiers from South Africa, Tanzania and Malawi.
AFP