UN rights chief Volker Turk issued a "red alert" Friday on the unfolding "catastrophe" in the Sudanese city of El-Obeid, where the United Nations fears an imminent paramilitary assault. Addressing an urgent debate at the UN Human Rights Council, Turk urged world leaders to take immediate action to prevent atrocity crimes. "The signs from El-Obeid are clear and unmistakable: another human rights catastrophe is unfolding in Sudan," he warned. "Civilians have been subjected to siege-like conditions for 18 months, battered by relentless drone strikes as the Sudanese Armed Forces and the Rapid Support Forces (RSF) battle for control. "This is not a drill. It is a red alert that needs to land on the desks of heads of state and government around the world. "Their phones should be running hot in the coming days." The UN's top rights body was holding a rare urgent debate on the human rights situation around El-Obeid, following a request by Britain on behalf of a group of countries. In recent days, the UN, several governments and aid organisations have warned of a possible RSF offensive on El-Obeid. 'Appalling suffering' Sudan's conflict erupted in April 2023 between the regular army and the paramilitary RSF. Kordofan – home to oil deposits and the RSF's most powerful paramilitary allies – remains a key battleground. El-Obeid, the capital of North Kordofan state, sits on a key route linking RSF-held areas in the western Darfur region to army-controlled regions in the east.