Fighting in Sudan's civil war could escalate further after the paramilitary Rapid Support Forces overran the army base in the western city of El Fasher, analysts and the UN warned on Monday.
The RSF, which has been at war with the army since April 2023, said on Sunday it had captured the garrison, the army's last foothold in the vast western region of Darfur.
The RSF also claimed to have captured the city of El Fasher, the capital of North Darfur province, where more than 250,000 people need humanitarian assistance.
Army chief and de facto ruler of Sudan Gen Abdel Fattah Al Burhan acknowledged in a TV broadcast late on Monday night that the garrison's troops and allied fighters had left El Fasher to spare the city and its residents "the systematic destruction and killing of civilians".
"They have decided to leave and we agreed they should leave the city and go somewhere safe so that they spare the remaining civilians and what is left of the city further destruction," said Gen Al Burhan, who vowed to retake the city and all RSF-held territory.
At a regional gathering in Malaysia, UN Secretary General Antonio Guterres warned of worse days ahead in Sudan's civil war after the fall of El Fasher.
"This represents a terrible escalation in the conflict," he said. "The level of suffering that we are witnessing in Sudan is unbearable."
The army's 6th Division and allied militias and former rebels have for months been fending off intense attacks by the RSF on El Fasher, including shelling and drone strikes.
There were reports on Monday that army troops and their allies had taken up new defence lines and were engaged in battles against the RSF, according to the Resistance Committees in El Fasher, a grassroots group tracking the war.
It said the fighting was taking place around the airfield of the base, as well as on the western side of the city.
In a statement late on Sunday, the Humanitarian Research Lab at Yale University said it had identified activity that appeared to substantiate reports of the RSF taking prisoners in and around the airfield.
Tom Fletcher, the UN emergency relief co-ordinator, expressed “deep alarm” at reports of civilian casualties and forced displacement in the city.
“Hundreds of thousands of civilians are trapped and terrified – shelled, starving, and without access to food, health care or safety,” he said.
Mr Fletcher called for “safe, rapid and unimpeded humanitarian access” to help those who remained in the city.
El Fasher has been the focus of Sudan's civil war since the army drove the RSF out of the capital and central Sudan this year. With its capture, the RSF now has full control over Darfur, a region the size of France, where it has set up a government of its own based in the city of Nyala.
The RSF also controls parts of Kordofan to the south-west, which analysts believe will be the next theatre of the war. Besides Khartoum and central Sudan, the army also controls the eastern and northern regions.
An army-backed government sits in the city of Port Sudan on the Red Sea, hundreds of kilometres from the nearest RSF positions, although its main infrastructure sites, including the airport and large fuel tanks, were hit by RSF drones this year.
"The RSF has now tightened its control over Darfur and is in a better position to make gains in Kordofan," said Sami Saeed, a US-based Sudan expert. "Its loss is a body blow to the army. That, in turn, will escalate the war and I expect the army to launch an intense aerial campaign against the RSF there."
"Besides being a significant political and military victory, it's a symbolic one," said Mr Saeed, who cited the history of the city as the traditional seat of the Sultan of the Fur, one of Sudan's largest and oldest tribes.
"Moreover, El Fasher has always been viewed as the capital of the whole of Darfur, not just North Darfur."
Another analyst, retired Sudanese Brig Gen Montassar Negmeldeen, also predicted that the war will escalate after the fall of El Fasher, with most future fighting taking place in Kordofan.
"The performance of the army in Darfur has been weak and its men there had not been sufficiently supplied," he said. "The loss of El Fasher will be remembered as a shameful chapter in the army's history because of what the city means."
The root cause of Sudan's civil war is the rivalry between Gen Al Burhan and his one-time ally Gen Mohamed Dagalo, the RSF commander.
Their disagreement over the assimilation of the paramilitary into the armed forces was at the heart of the quarrel that boiled over into open warfare in April 2023.
The war has killed tens of thousands and displaced more than 13 million. The UN's latest figures show that about 30 million people – more than half the population − are facing hunger, with famine afflicting some areas, mostly in Darfur.
The RSF and the army are accused of war crimes, including ethnic cleansing, sexual assaults, indiscriminate shelling and extrajudicial executions, and their leaders have been placed under sanctions by the US.
Al Shafie Ahmed contributed to this report from Kampala, Uganda.
