Artillery blasts rang out Wednesday in Khartoum, after the Sudanese army suspended its participation in US and Saudi-brokered ceasefire talks, accusing its paramilitary foes of failing to honour their commitments.
The mediators of the talks in the Saudi Red Sea city of Jeddah have acknowledged repeated violations of the truce by both sides but have so far held off imposing any sanctions in the hope of keeping the warring parties at the negotiating table.
The army walked out "because the rebels have never implemented a single one of the provisions of a short-term ceasefire which required their withdrawal from hospitals and residential buildings", a Sudanese government official said.
It also took the decision because the paramilitary Rapid Support Forces (RSF) had "repeatedly violated the truce", added the official who spoke on condition of anonymity.
A witness said there was "heavy artillery fire from army camps" in northern Khartoum on Wednesday, two days after US and Saudi mediators said the warring parties had agreed to extend by five days a humanitarian truce they had frequently violated over the previous week.
The mediators admitted the truce had been "imperfectly observed" but said the extension "will permit further humanitarian efforts".
But despite the pledges of both sides, fighting flared again on Tuesday both in greater Khartoum and in the flashpoint western region of Darfur.
"The army is ready to fight until victory," army chief Abdel Fattah al-Burhan declared during a visit to troops in the capital.
The RSF, led by Burhan's deputy-turned-foe Mohamed Hamdan Daglo, said they would "exercise their right to defend themselves" and accused the army of violating the truce.
Fears of breakdown
Sudan specialist Aly Verjee said the mediators were eager to avoid a complete breakdown of the talks, for fear of a major escalation on the ground.
"The mediators know that the situation is bad but they do not want to state that a ceasefire is gone for fear that the situation would then become even worse," said Verjee, a researcher at Sweden's University of Gothenburg.
"The hope is that by keeping the parties talking, the prospects of arrangements that are better respected will eventually improve."
Since fighting erupted between the rival security forces on April 15, more than 1,800 people have been killed, according to the Armed Conflict Location and Event Data Project.
The United Nations says 1.2 million people have been internally displaced and over 425,000 have fled abroad.
More than half the population -- 25 million people -- are now in need of aid and protection, the UN says.
Entire districts of Khartoum no longer have running water, electricity is only available for a few hours a week, and three quarters of hospitals in combat zones are out of service.
Health facilities out of service -
The health ministry said Wednesday that "nine health facilities" had gone out of service in Jazira state, just south of Khartoum, "despite the declared truce".
In a statement, the ministry said the closures were due to "the presence of RSF militias threatening the movement of medical personnel and supplies".
Many families have continued to hide out in their homes, rationing water and electricity while trying desperately to avoid stray gunfire in the city of more than five million people -- nearly 700,000 of whom have fled, according to the United Nations.
In Darfur, on Sudan's western border with Chad, continued fighting "blatantly disregards ceasefire commitments", said Toby Harward, of the UN refugee agency.
The persistent fighting has impeded delivery of the aid and protection needed by a record 25 million people, more than half the population, according to the UN.
Despite the increasing needs, it says it has only received 13 percent of the $2.6 billion it requires.
The UN has warned for weeks that fighting in Darfur's major cities has also drawn in former rebel and militia fighters recruited along ethnic lines during the region's devastating conflict in the mid-2000s.
Darfur's pro-army governor Mini Minawi, a former rebel leader, has urged citizens to "take up arms" to defend their property.
Sudan could descend into "total civil war", warned the Forces for Freedom and Change, the main civilian bloc ousted from power by Burhan and Daglo in a 2021 coup before the two men fell out.