The United Nations issued a "stark warning" Friday over preparations for intensified fighting in Sudan's Kordofan region, as it made a new call for an end to the violence.
The paramilitary Rapid Support Forces (RSF), who have been locked in conflict with Sudan's regular army since April 2023, announced on Thursday that they had agreed to a humanitarian truce proposal made by mediators.
Following the RSF capture of el-Fasher in late October of the army's last major stronghold in the western Darfur region, the paramilitaries appear to be shifting their focus eastward towards Khartoum and oil-rich Kordofan.
UN human rights chief Volker Turk said traumatized and trapped civilians were being prevented from leaving el-Fasher.
"I fear that the abominable atrocities such as summary executions, rape and ethnically motivated violence are continuing within the city," he said in a statement.
And for those who do manage to escape, the exit routes have been the scenes of "unimaginable cruelty", he added.
"At the same time, I issue a stark warning about events unfolding in Kordofan," said Turk.
"Since the capture of el-Fasher, the civilian casualties, destruction and mass displacement there have been mounting. There is no sign of de-escalation.
"To the contrary, developments on the ground indicate clear preparations for intensified hostilities, with everything that implies for its long-suffering people."
The RSF have been accused of mass killings, looting and sexual violence in el-Fasher.
Turk said that given the "cataclysmic violence" in the city, countries were on notice that without quick and decisive action, "there will be more of the carnage and atrocities that we have already witnessed".
He said the provision of military support to sustain parties committing serious violations must stop.
"I repeat my plea for an immediate end to the violence both in Darfur and Kordofan. Bold and urgent action is required by the international community," said Turk.
The fall of el-Fasher gave paramilitaries control over all five state capitals in Darfur, raising fears that Sudan would effectively be partitioned along an east-west axis.
