Battling fighters in Sudan said Sunday they had begun an hours-long humanitarian pause, including to evacuate wounded, on the second day of raging urban battles that killed more than 50 civilians, including three UN staff, and sparked international outcry.
After the killing of the three World Food Programme workers the agency said it was suspending operations in the impoverished country.
Deafening explosions and intense gunfire rattled buildings in the capital Khartoum's densely-populated northern and southern suburbs as tanks rumbled on the streets and fighter jets roared overhead, witnesses said.
Violence erupted early Saturday after weeks of power struggles between army chief Abdel Fattah al-Burhan and his deputy, Mohamed Hamdan Daglo, commander of the heavily-armed paramilitary Rapid Support Forces (RSF).
Each accused the other of starting the fight.
The Central Committee of Sudan Doctors said they had recorded 56 civilians killed as well as "tens of deaths" among security forces, and around 600 wounded.
Late Sunday afternoon the army said they had "agreed to a United Nations proposal to open safe passage for humanitarian cases", including the evacuation of wounded, for three hours from 1400 GMT.
RSF issued a separate statement saying they had agreed to the measure, though they said it would last four hours, and both sides maintained their right to "respond in the event of transgressions" from the other side.
One hour into the agreed pause, heavy gunfire could still be heard in central Khartoum near the airport.
"The gunfire and explosions are incessant," said 34-year-old Ahmed Hamid from a northern Khartoum suburb.
"The situation is very worrying and it doesn't seem like it will calm anytime soon," said Ahmed Seif, another Khartoum resident, who said it was too dangerous to go outside.
Both sides claim they control key sites. Daglo's RSF say they have seized the presidential palace, Khartoum airport and other strategic locations, but the army insist they are still in control.
Footage obtained by AFP showed heavy smoke billowing from a building near the army headquarters in Khartoum, with the military saying a building had "caught fire" amid the clashes but that it had been contained.
On Sunday, the stench of gunpowder wafted through Khartoum's streets, deserted except for soldiers as frightened civilians sheltered inside their homes.
Medics had pleaded for safe corridors for ambulances and a ceasefire to treat the victims. They warned the streets were too dangerous to bring many casualties to hospitals.
Fighting has also erupted outside Khartoum, including in the western Darfur region and in the eastern border state of Kassala, where witness Hussein Saleh said the army had fired artillery at a paramilitary camp.
The UN said its WFP employees had been killed Saturday in clashes in North Darfur, announcing a "temporary halt to all operations in Sudan".
UN Secretary-General Antonio Guterres had warned on Saturday that an escalation in the fighting would "further aggravate the already precarious humanitarian situation in the country."
The UN says one-third of Sudan's population need humanitarian aid.
UN Special Representative Volker Perthes condemned the killings and said he was also "appalled by reports of projectiles hitting UN and other humanitarian premises in several locations in Darfur".
WFP said an aircraft managed by the organisation "was also significantly damaged" at Khartoum airport.
Announcing the suspension of work in the country, the agency's head Cindy McCain said: "We cannot do our lifesaving work if the safety and security of our teams and partners is not guaranteed."
Created in 2013, the RSF emerged from the Janjaweed militia that then-president Omar al-Bashir unleashed against non-Arab ethnic minorities in Darfur a decade earlier, drawing accusations of war crimes.
The RSF's planned integration into the regular army was a key element of talks to finalise a deal that would return the country to civilian rule and end the political-economic crisis sparked by the military's 2021 coup.
US Secretary of State Antony Blinken said the fighting "threatens the security and safety of Sudanese civilians".
Similar appeals came from the African Union, Britain, China, the European Union and Russia, while Pope Francis said he was following the events "with concern" and urged dialogue.
The AU is to hold an emergency meeting on Sunday, as is the Arab League, following a request by Egypt and Saudi Arabia.
But the two generals appear in no mood for talks. In an interview with UAE-based Sky News Arabia, Daglo, also known as Hemeti, said, "Burhan the criminal must surrender".
The army declared Daglo a "wanted criminal" and the RSF a "rebel militia", saying there "will be no negotiations or talks until the dissolution" of the group.
The latest violence, during the Muslim fasting month of Ramadan, came after more than 120 civilians had already been killed in a crackdown on regular pro-democracy demonstrations over the past 18 months.
The October 2021 coup triggered international aid cuts and sparked near-weekly protests.
Burhan, who rose through the ranks under the three-decade rule of now jailed general Bashir, has said the coup was "necessary" to include more factions into politics.
Daglo later called the coup a "mistake" that failed to bring about change and reinvigorated remnants of Bashir's regime ousted by the army in 2019 following mass protests.
Sudanese greet army soldiers, loyal to army chief Abdel Fattah al-Burhan, in the Red Sea city of Port Sudan on April 16, 2023. AFP