The United Nations said on Wednesday more than half Sudan's population now needed aid and protection, as civilians sought shelter from air strikes and sporadic clashes between rival military factions in the Khartoum area.
Residents said power had been cut, food was in short supply, and drinking water scarce due to the violent power struggle, now in its second month despite international mediation efforts.
Launching an appeal for some $3 billion in aid, the United Nations said 25 million people needed help - the highest number ever recorded in Sudan, where around 15 million needed aid before the conflict.
Signalling no let-up in the conflict between the Sudanese army and the paramilitary Rapid Support Forces (RSF), anti-aircraft guns and drones could be heard on Wednesday in the capital, residents reported.
"We have been moving from one place to the other in past days," said 27-year-old Abbas al-Sayyed, speaking to Reuters by phone from Bahri, a city adjoining the capital Khartoum, epicentre of a conflict that has killed hundreds of people.
"There is no electricity, no water at all, and even the bread we used to get in the first days of the war, we can’t get now. We can't move out," he said.
Clashes continued around Al-Jaili in Bahri, home to the country's largest oil refinery, residents said, and more violence was reported in El-Obeid in North Kordofan State, southwest of Khartoum.
The army led by General Abdel Fattah al-Burhan has been using air strikes and shelling in a bid to root out RSF fighters under the command of General Mohamed Hamdan Dagalo, known as Hemedti, who are entrenched in residential areas of Khartoum.
On Tuesday the army released a video showing Burhan dressed in army fatigues with a rifle slung over his back, greeting troops at what appeared to be the army headquarters in Khartoum. Reuters could not immediately verify the video.
Across Sudan, the fighting has uprooted around 1 million people, 220,000 of whom have fled into neighbouring states.
Talks mediated by the United States and Saudi Arabia in Jeddah have so far failed to secure a ceasefire.
The sides agreed last week to a statement of principles on protecting civilians and allowing aid supplies, but arrangements for humanitarian corridors and agreeing a truce are still being discussed. Several previous ceasefires have failed to stop the fighting.
The conflict is likely to feature on the agenda of an Arab Summit hosted by Saudi Arabia on Friday. Sudan is expected to be represented by special envoy Dafallah Alhaj while Burhan, the de facto head of state, will remain in Sudan.
"We don't feel safe, we're in a state of fear," said Saad Eldin Youssef, a 45-year-old resident of Omdurman, a city across the Nile from Khartoum.
"The Rapid Support Forces are spread out on the ground around us and planes are carrying out strikes in neighbourhoods continuously."
'EVERYTHING IS RUNNING OUT'
Ramesh Rajasingham, head of OCHA in Geneva, said the appeal for nearly $2.6 billion for operations from May until October was the highest ever for Sudan. The U.N. refugee agency (UNHCR) said it was seeking $472 million to assist more than 1 million people over the next six months.
With aid agencies unable to access the capital, the distribution of medical aid, food and fuel in the Khartoum area has fallen to local groups known as resistance committees.
"We did not receive any humanitarian aid from NGOs locally or internationally," said Mohammed Elobaid, an organiser in Omdurman, speaking in a recorded statement screened during the U.N aid appeal.
"What we can see here is that the situation is even going to get worse because medical supplies and food supply - everything is running out."
Burhan and Hemedti took the top positions on Sudan's ruling council following the 2019 overthrow of strongman Omar al-Bashir in a popular uprising. They staged a coup two years later as a deadline to hand power to civilians approached and began to mobilise their respective forces.
The conflict erupted after disputes over plans for the RSF to join the army and the future chain of command under an internationally backed deal for a political transition towards civilian rule.