The armed forces of the United States and the United Kingdom have evacuated embassy staff from Sudan, while other nations rushed to get their citizens to safety as rival military factions battled in the capital Khartoum on Sunday.

The eruption of fighting eight days ago between the army and the Rapid Support Forces (RSF) paramilitary group has triggered a humanitarian crisis, killed 420 people and trapped millions of Sudanese without access to basic services.

As people attempted to flee the chaos, countries began landing planes and organising convoys in Khartoum to pull out their nationals. Some foreign citizens were injured. Gunfire rang out across the city and dark smoke hung overhead, a Reuters reporter said.

The warring sides accused each other of attacking a French convoy, both saying one French person was wounded. France's Foreign Ministry, which had earlier said it was evacuating diplomatic staff and citizens, did not comment.

France said a French plane carrying around a hundred people including the European Union delegation in Khartoum along with other nationalities had left for Djibouti, and a second plane with a similar number aboard was due to take off shortly.

The risks were also evident in army accusations that the RSF looted a Qatari convoy heading to Port Sudan. In separate incidents, an Iraqi citizen was killed during clashes and Egypt said one of its diplomats had been wounded.

The efforts to extract foreign residents frustrated some Sudanese who felt the rival factions showed less concern for the safety of locals.

"Seeing the foreigners leave made me upset because I see there's some groups that were helped by the army and RSF, meanwhile we keep getting hit," said Alsadig Alfatih, who on Sunday managed to leave his home for the first time since the fighting erupted and said he would head to Egypt.

The Sudanese army said it worked with the United States, the United Kingdom, Germany and France on evacuation operations at Wadi Sedna, an air base north of Khartoum. Qatar and Jordan's operations were conducted overland to Port Sudan, the army said.

Canada had also extracted its diplomats and was trying to support its local staff, Prime Minister Justin Trudeau said.

Egypt, India, Nigeria and Libya were among the countries that said they were working to bring home their people.

Pope Francis appealed for an end to the violence during his Sunday midday prayer in Rome.

The fighting broke out in Khartoum and other parts of the country on April 15, four years after long-ruling autocrat Omar al-Bashir was toppled.

The army and RSF jointly staged a coup in 2021 but fell out during negotiations to integrate the two groups and form a civilian government.

US officials said its special forces evacuated fewer than 100 people on Saturday in an operation that took just one hour on the ground.

"We did not take any small-arms fire on the way in and were able to get in and out without issue," said Lieutenant General Douglas Sims.

CEASEFIRE BREACHED

Sudan's sudden collapse into warfare has dashed plans to restore civilian rule, brought an already impoverished country to the brink of humanitarian disaster, and threatened a wider conflict that could draw in outside powers.

Beyond Khartoum, reports of the worst violence have come from Darfur, a western region bordering Chad that suffered 300,000 people dead and 2.7 million displaced during an earlier conflict that started in 2003.

The army under Abdel Fattah al-Burhan, and the RSF, headed by Mohamed Hamdan Dagalo, known as Hemedti, have failed to observe ceasefires reached almost daily, including a three-day truce for the Muslim holiday of Eid al-Fitr, which began on Friday.

For the first time since the start of the fighting, a video was posted that briefly showed Hemedti in battle dress in the passenger seat of a pick-up truck, surrounded by cheering troops, near Khartoum's presidential palace.

Reuters was able to confirm the location, but was not able to independently verify the date the video was filmed.

Burhan said on Monday he was based at the army headquarters in central Khartoum, about 2 km (1.2 miles) from the palace.

Battles have continued around the army's headquarters and the airport, which has been closed by the clashes, and over the past two days in Bahri, where the army has used troops on the ground as well as air strikes to try to push back the RSF.

The RSF said on Sunday its forces were targeted by air strikes in Bahri's Kafouri district and that dozens were killed and injured.

RSF forces were heavily deployed on the streets and on bridges across the capital, with army troops visible in parts of Omdurman, a Reuters reporter said. Neighbourhoods were otherwise largely empty of civilians and ordinary life.

In Bahri, a video verified by Reuters showed a major market burning. Residents reported looting in the district, which is home to industrial zones containing important flour mills.

World Health Organisation head Tedros Ghebreyesus described multiple deadly attacks on health facilities. "Paramedics, frontline nurses and doctors are often unable to access the wounded and the injured cannot reach facilities," he tweeted.

The WHO retweeted a post from Sudan's Health Ministry on Sunday saying at least 420 people had been killed and 3,700 injured in the fighting so far.