Sudanese in the capital Khartoum and other cities have huddled in their homes for a third day, as explosions and gunfire thundered outside and the army and a powerful rival force battled in the streets for control of the country.
At least 185 people have been killed and over 1,800 wounded since the fighting erupted, UN envoy Volker Perthes said.
The two sides are using tanks, artillery and other heavy weapons in densely populated areas.
Fighter jets swooped overhead and anti-aircraft fire lit up the skies as darkness fell.
There has been no official word on how many civilians or combatants have been killed.
The doctors’ syndicate earlier put the number of civilian deaths at 97.
The sudden explosion of violence over the weekend between the nation’s two top generals, each backed by tens of thousands of fighters, trapped millions of people in their homes or wherever they could find shelter, with supplies running low in many areas.
Top diplomats on four continents scrambled to broker a truce, with the UN Security Council set to discuss the crisis.
“Gunfire and shelling are everywhere,” Awadeya Mahmoud Koko, head of a union for thousands of tea vendors and other food workers, said from her home in a southern district of Khartoum.
She said a shell struck a neighbour’s house on Sunday, killing at least three people.
“We couldn’t take them to a hospital or bury them.”
Nearby, at least 88 students and staff have been trapped in the engineering college library at Khartoum University since the start of the fighting, one of the students said in a video posted online on Monday.
One student was killed during clashes outside and another wounded, he said.
They do not have food or water, he said, showing a room full of people sleeping on the floor.
Even in a country with a long history of military coups, the scenes of fighting in the capital and its adjoining city Omdurman across the Nile River were unprecedented.
The turmoil comes just days before Sudanese were to celebrate Eid al-Fitr, the holiday marking the end of Ramadan, the Islamic month of fasting.
The power struggle pits General Abdel-Fattah Burhan, the commander of the armed forces, against General Mohammed Hamdan Dagalo, the head of the Rapid Support Forces, a paramilitary group.
The former allies jointly orchestrated an October 2021 military coup that derailed Sudan’s transition to democracy.
The US, the UN and others have called for a truce.
Egypt, which backs Sudan’s military, and Saudi Arabia and the United Arab Emirates – which forged close ties to the RSF in recent years as it sent thousands of fighters to support their war in Yemen – have also called for both sides to stand down.
But both generals have thus far dug in, demanding the other’s surrender and ruling out negotiations.
The European Union’s foreign policy chief, Josep Borrell, tweeted that the EU ambassador to Sudan “was assaulted in his own residency”, without providing further details.
Gen Dagalo, whose forces grew out of the notorious Janjaweed militias in Sudan’s Darfur region, portrayed himself in a statement on Twitter on Monday as a defender of democracy and branded Gen Burhan as the aggressor and a “radical Islamist”.
Both generals have a long history of human rights abuses and have cracked down on pro-democracy activists.
Heavy gunbattles raged in multiple parts of the capital and Omdurman, where the two sides have brought in tens of thousands of troops, positioning them in nearly every neighbourhood.
Twelve hospitals in the capital area have been “forcefully evacuated” and are “out of service” because of attacks or power outages, the Sudan Doctors’ Syndicate said, out of a total of around 20 hospitals.
Four other hospitals outside the capital have also shut down, it added in a statement late on Monday.
They have food for a few more days, but “after that we don’t know what to do”, she said.
Residents said fierce fighting with artillery and other heavy weapons raged on Monday afternoon in the Gabra neighbourhood south-west of Khartoum.
People were trapped and screaming inside their homes, said Asmaa al-Toum, a physician living in the area.
Fighting has been particularly fierce around each side’s main bases, located amid civilian areas, and at strategic government buildings.
The military on Monday claimed to have secured the main television building in Omdurman, fending off RSF fighters trying to seize the building for days.
State-run Sudan TV resumed broadcasting.
The military scored a significant gain on Sunday when the RSF said it abandoned its main barracks and base, in Omdurman, which the armed forces had pounded with air strikes.
The authenticity of the videos could not be confirmed independently.
The military and RSF were also fighting in most major centres around the country, including in the western Darfur region and parts of the north and the east, by the borders with Egypt and Ethiopia.
Battles raged on Monday around a strategic airbase in Merowe, some 350 kilometres (215 miles) north-west of the capital, with both sides claiming control of the facility.
Only four years ago, Sudan inspired hope after a popular uprising helped depose long-time autocratic leader Omar al-Bashir.
But the turmoil since, especially the 2021 coup, has frustrated the democracy drive and wrecked the economy.
A third of the population – around 16 million people – now depends on humanitarian assistance in the resource-rich nation, Africa’s third largest.
Save the Children, an international charity, said it has temporarily suspended most of its operations across Sudan.
It said looters raided its offices in Darfur, stealing medical supplies, laptops, vehicles and a refrigerator.
With the US, European Union, African and Arab nations all calling for an end to fighting, the UN Security Council was to discuss the developments in Sudan later.
UN secretary-general Antonio Guterres said he was consulting with the Arab League, African Union and leaders in the region, urging anyone with influence to press for peace.
Egyptian foreign minister Sameh Shoukry discussed the violence in separate phone calls with his Saudi and French counterparts, the Egyptian Foreign Ministry said.
At a meeting of the Group of Seven wealthy nations in Japan on Monday, US secretary of state Antony Blinken said the Sudanese “want the military back in the barracks. They want democracy. They want the civilian-led government, Sudan needs to return to that path”.
Under international pressure, Gen Burhan and Gen Dagalo had recently agreed to a framework agreement with political parties and pro-democracy groups.
However, the deal was vague on key points of dispute, including how the RSF would be integrated into the armed forces and who would have final control.
The signing of the deal was put off repeatedly as tensions rose between the generals.