The fight for the Sudanese city of El-Fasher has raised concerns about an imminent large-scale massacre in the humanitarian hub in the Darfur region.

Violent clashes have been reported in El-Fasher and surrounding villages since mid-April. The city had been relatively calm since the war erupted in Sudan last year between the army and a rival paramilitary force.

Reports say the fighters loyal to the Rapid Support Forces (RSF) are preparing for an “imminent assault” on El-Fasher.

El-Fasher “is on the precipice of a large-scale massacre. This is not conjecture. This is the grim reality facing millions of people,” Linda Thomas-Greenfield, the US ambassador to the United Nations, told journalists following a UN Security Council meeting on Sudan on Monday.

“There are already credible reports that the RSF and its allied militias have razed multiple villages west of El-Fasher, and as we speak, the RSF is planning an imminent attack on El-Fasher,” which “would be a disaster on top of a disaster,” Thomas-Greenfield said.

The RSF has been fighting the army, led by Gen. Abdel Fattah Burhan, for control of the North African country since April 15 last year in a war that has killed thousands of people and displaced eight million amid warnings of famine.

El-Fasher is the latest flashpoint in a year-old war between Sudan’s military and the Rapid Support Forces.

Foreign powers are accused of fueling the fight, especially the United Arab Emirates.

UN sanctions monitors have described as “credible” accusations that the United Arab Emirates had provided military support to the RSF, a charge the UAE denies.

El-Fasher functions as the main humanitarian hub in the vast western region of Darfur, home to around a quarter of Sudan’s 48 million people.

Earlier this month, top United Nations officials warned the Security Council that about 800,000 individuals residing around El-Fasher are currently facing an alarming and imminent threat.

“Fighting in El-Fasher could unleash bloody intercommunal strife throughout Darfur,” Rosemary DiCarlo, political affairs chief of the UN, said on April 19.

“The violence poses an extreme and immediate danger to the 800,000 civilians who reside in El Fasher,” also warned the UN aid operations director, Edem Wosornu.