An extensive earthen wall is being built around the besieged Sudanese city of el-Fasher and is intended to trap people inside, according to research from Yale University.
From satellite images, the university's Humanitarian Research Lab has identified more than 31km (19 miles) of berms - as the raised banks are known - constructed since May in territory outside the city occupied by the paramilitary Rapid Support Forces (RSF).
El-Fasher, under siege for more than a year, is the last major foothold in Darfur for the army, which has been battling the RSF since April 2023.
The Sudan Doctors Network has told the BBC that the RSF is intensifying its offensive there and deliberately targeting civilians.
Yesterday there was a shelling in a civilian area down in the city centre that ended up killing almost 24 civilians and injuring 55 people, among them five women, Dr Mohamed Faisal Hassan, from the medics association, told the BBC's Newsday programme.
The attacks on the central market and a residential area were deliberate and heinous, he said.
BBC Verify reports that both sides in the conflict have been using berms as a defensive strategy. However, the analysis by Yale's Humanitarian Research Lab suggests that the RSF is creating a literal kill box around el-Fasher.
The report highlights the ongoing physical boundary deepening siege conditions and controlling who can enter or leave the city. Civilians are experiencing food scarcity, medical access hardships, and ongoing bombardment as humanitarian access remains cut off.
With the construction of these walls, the RSF is believed to have established tactical conditions aimed at defeating the army division in el-Fasher. The fall of the city would lead to complete RSF control over western Darfur, posing a critical threat of further partitioning the country.
Throughout this conflict, the RSF and allied militia have been accused of targeting civilians, particularly those from non-Arab ethnic groups. Dr Hassan noted that many civilians attempting to escape are being targeted and killed by RSF forces, while those remaining face a dire situation with little hope for aid or escape.
The Humanitarian Research Lab's report underscores the critical need for international attention and protection for the civilians trapped in the ongoing conflict in Sudan.
