At least 16 people have been killed in an artillery bombardment of a besieged city in Sudan’s embattled Kordofan region, adding to a mounting civilian death toll as the country’s brutal civil war enters a critical phase deep into its third year.

The Rapid Support Forces (RSF) and their allies in the Sudan People’s Liberation Movement-North (SPLM-N) shelled residential areas of Dilling in South Kordofan over the past two days into Friday, according to the Sudan Doctors Network, a medical monitoring group.

Women, elderly residents and children were among those killed in what the group condemned as the deliberate targeting of civilians.

The attack on Dilling is part of an escalating campaign of violence across Kordofan that has killed more than 100 civilians since early December, as fighting in Sudan’s war has shifted from the western Darfur region to the strategic central heartland, where the conflict’s outcome will be decisively affected.

The Sudan Doctors Network called on the international community to pressure both armed groups to immediately halt attacks on civilian areas and ensure humanitarian access to those trapped by the fighting.

The bombardment has increased the crippling strain on health facilities already overwhelmed by cholera and dengue fever outbreaks in a city that has endured a siege lasting more than two years.

More than 50,000 people have fled violence across Kordofan’s three states since late October, when the RSF captured a major army base and intensified operations in the region, according to the International Organization for Migration.

Some 710 people have been displaced from Dilling alone during this period, with many arriving in neighbouring areas with nothing after witnessing what United Nations refugee officials described as “unspeakable horrors”.

The violence prompted UN human rights chief Volker Turk to warn earlier this month that history was “repeating itself” in Kordofan following mass atrocities in Darfur, notably in el-Fasher, which the UN has described as a “crime scene”.

Six Bangladeshi peacekeepers were killed when drones struck their base in Kadugli, South Kordofan’s capital, on December 13. The attack, which UN Secretary-General Antonio Guterres said “may constitute war crimes”, has forced the UN mission to evacuate its logistics base there after determining the security situation had made operations untenable.

The RSF has established a pattern of systematic atrocities throughout the war. The government-aligned Sudanese Armed Forces (SAF) has also been accused of atrocities in the war.

A UN report released on Thursday detailed how the RSF paramilitary force killed more than 1,000 civilians during a three-day assault on the Zamzam displaced persons camp in Darfur in April, using sexual violence as what investigators called a deliberate tool of terror. The camp was almost completely emptied of its population.

Sudan’s conflict, which erupted in April 2023 between SAF chief Abdel Fattah al-Burhan and his former deputy, Mohamed Hamdan “Hemedti” Dagalo, has, according to some monitors, killed more than 100,000 people and displaced 14 million in what the UN terms the world’s largest humanitarian crisis.

Against this backdrop, al-Burhan travelled to Cairo on Wednesday, where Egyptian President Abdel Fattah el-Sisi received him with full ceremonial honours at the airport.

Egypt warned it would not allow what it called “red lines” to be crossed in neighbouring Sudan, citing concerns over territorial integrity and parallel governments after the RSF declared a rival administration in Darfur.

Cairo invoked its right under a 1976 joint defence pact to take necessary measures to protect its national security, which it said is “inextricably linked” to Sudan’s stability.

Egypt backed renewed United States diplomatic efforts, with Secretary of State Marco Rubio discussing an urgent humanitarian ceasefire with Emirati officials on Wednesday. Sudanese officials, UN experts and war monitors have accused the United Arab Emirates of backing the RSF, which Abu Dhabi has repeatedly denied.