The UN warns that fighting between the army and the RSF risks causing a humanitarian catastrophe that could spill into other countries.

Fierce fighting is continuing in Khartoum, Sudan, as the army tries to push back the paramilitary Rapid Support Forces (RSF) from around the presidential palace and army headquarters, in spite of a supposed seven-day ceasefire in the conflict that erupted on April 15.

Heavy bombardments were also reported on Thursday in Khartoum’s sister cities of Omdurman and Khartoum.

Sudanese reports on Tuesday said 550 people had died and 4,926 people wounded so far in the conflict.

The sides appear to be battling for territory in the capital before any possible negotiation, though the two leaders – army chief General Abdel Fattah al-Burhan and RSF leader General Mohamed Hamdan “Hemedti” Dagalo – have shown little willingness to hold talks.

Al-Burhan’s envoy Dafallah Alhaj told Al Jazeera that the agreement had been only to a ceasefire, “not to mediation regarding the resolution of the conflict”.

“To us, the final resolution will be decided on the ground. Our delegation will not engage in direct talks or even open a channel of communication with the rebels,” he said.

A stillborn ceasefire

Earlier this week, Sudan’s warring factions agreed in principle to a seven-day ceasefire from Thursday, but more air raids and shooting in the Khartoum region disrupted that.

The credibility of the May 4-11 deal ceasefire deal between the two has been in doubt given the violations that undermined previous, shorter agreements.

The United Nations, meanwhile, pressed Sudan’s warring factions on Wednesday to guarantee safe passage of humanitarian aid after six trucks were looted.

UN aid chief Martin Griffiths said he hoped to have face-to-face meetings with Sudan’s warring parties within two to three days to secure guarantees from them for aid convoys.

Thousands of UN workers were evacuated a week into the fighting, and some UN agencies paused their services. The World Food Programme (WFP) suspended operations after three of its workers were killed in fighting in southern Sudan, but the agency has since said it will resume its work.

It remains unclear how UN agencies can operate with limited staff and supplies amid the chaos.

Humanitarian disaster

The UN warns that fighting between the army and the RSF risks causing a humanitarian catastrophe that could spill into other countries.

Before the fighting erupted, a third of Sudan’s population of more than 45 million relied on humanitarian assistance, according to UN agencies, already suffering funding shortfalls.

About 100,000 people have fled Sudan to neighbouring countries, the UN says, with more than 42,000 Sudanese crossing into Egypt along with 2,300 foreign nationals since the crisis began.

Aid workers are increasingly concerned about the lack of basic services in Sudan’s border areas and in Port Sudan, some 800km (500 miles) from Khartoum.

The WFP reported that 17,000 metric tonnes of food of the 80,000 metric tonnes it has in Sudan have been looted, including in Khartoum and Western Darfur, UN deputy spokesman Farhan Haq said on Wednesday.

For those who cannot leave Khartoum, basic goods have become unavailable or unaffordable. Aid organisation Mercy Corps said on Wednesday that prices of basic goods in the city increased more than 130 percent on average, while fuel prices increased more than tenfold.