The visit by top UN humanitarian official Martin Griffiths on Wednesday comes a day after neighbouring South Sudan announced that the warring sides had agreed “in principle” to a seven-day ceasefire.
Deadly violence broke out on April 15 between Sudan’s de facto leader Abdel Fattah al-Burhan, who commands the regular army, and his deputy-turned-rival Mohamed Hamdan Dagalo, or Hemedti, who commands the RSF.
At least 550 people have been killed and 4,926 wounded, according to Wednesday’s latest health ministry figures, which are likely to be incomplete.
Multiple hospitals have been hit, humanitarian facilities looted and foreign aid groups forced to suspend most of their operations. Tens of thousands of Sudanese have fled to neighbouring countries in an exodus that has sparked warnings of a humanitarian “catastrophe” with implications for the entire region.
Reporting from Khartoum, Al Jazeera’s Hiba Morgan said intense fighting had continued throughout the morning, with witnesses reporting a powerful explosion near the presidential palace and clouds of smoke rising from the area in the capital.
“It looks as though the Sudanese army is trying to regain control over the presidential palace. The two sides have been fighting around its vicinity. Fighter jets have been launched, not just near the presidential palace, but also around other parts of Khartoum,” said Morgan.
Fierce clashes were also reported near the state broadcaster’s headquarters in the capital’s twin city of Omdurman, while explosions and anti-aircraft guns were also heard in the city of Bahri, north of Khartoum.
Meanwhile, Griffiths arrived in Port Sudan on the Red Sea coast on an urgent mission to find ways to bring relief to the millions of Sudanese who are unable to flee.
“We will still require agreements and arrangements to allow for movement of staff and supplies,” he told reporters via video link from Port Sudan.
“We will need to have agreement at the highest level and very publicly and we will need to deliver those commitments into local arrangements that can be depended on.”
Aid deliveries have been held up in Sudan, where about one-third of people already relied on humanitarian assistance. A broader disaster could be in the making as refugees from Sudan cross into its impoverished neighbouring countries.
On Tuesday, the foreign ministry of South Sudan announced that al-Burhan and Dagalo “have agreed in principle for a seven-day truce from May 4th to 11th”.
The two sides have yet to formally confirm the new ceasefire.
The two men have agreed on multiple truces since the fighting began, but none has effectively taken hold. The current truce was extended on Sunday by a further 72 hours and is due to expire on Wednesday at midnight or 22:00 GMT.
The failure of the warring sides to abide by their commitments in efforts to end nearly three weeks of fighting has drawn mounting international criticism.
“The two generals, even though they accept the ceasefire, at the same time they continue fighting and shelling the city,” complained Ismail Wais, of the East African regional bloc Intergovernmental Authority on Development (IGAD).
He said the persistent fighting “compounds and complicates the political, security and humanitarian situation on the ground making it harder to resolve”.
The UN’s Griffiths also called for civilians and aid workers to be protected.
“Ensure safe passage for civilians fleeing areas of hostilities. Respect humanitarian workers and assets,” he said on Twitter.
Griffiths said he had been told by the World Food Programme that six WFP trucks travelling to Darfur were looted en route despite assurances of safety and security.
There was no immediate comment from WFP.
“It’s a volatile environment, so we need those commitments,” Griffiths said.
“It’s not as if we’re asking for the moon. We’re asking for the movement of humanitarian supplies, of people. We do this in every other country, even without ceasefires. It’s a traditional humanitarian enterprise to go where others don’t.”
Violence has also engulfed the Darfur region, with at least 99 people killed in fighting, according to Sudan’s doctors union.
Of the more than 330,000 people displaced inside Sudan, some 70 percent were reported to be from West and South Darfur states, according to the International Organization for Migration.
Darfur is still scarred by a war that erupted in 2003 when then-ruler Omar al-Bashir unleashed the so-called Janjaweed militia, mainly recruited from Arab pastoralist tribes, against ethnic minority rebels.
The Janjaweed – whose actions led to war crimes charges against al-Bashir and others – later evolved into the RSF.