Sudan has seen 10 days of fierce fighting after months of rising tensions between rival factions of the armed forces spiralled into an all-out battle for control of the country. Yet another ceasefire, a three-day truce for the Muslim Eid al-Fitr holiday agreed on Friday, fell apart the next day.

Both General Abdel Fattah al-Burhan, the Sudanese army chief, leader of the Sovereign Council and de facto ruler of the country, and his deputy Mohamed Hamdan Dagalo, who heads the paramilitary Rapid Support Forces (RSF) have pledged to fight each other to the end.

United Nations figures show that more than 420 people have been killed, including at least 256 civilians, and more than 3,500 wounded since fighting broke out on April 15. Sudan’s doctors’ union said that shelling in the capital Khartoum, its twin city of Omdurman and neighbouring states has destroyed or damaged hospitals, while others have been ransacked, rendering more than two-thirds of medical facilities “out of service.”

The International Committee of the Red Cross (ICRC) and the Sudanese Red Crescent Society said they were “closely monitoring the humanitarian situation in Khartoum and other parts of the country.”

“We are extremely worried that the fighting is affecting densely populated areas. People are seeking cover in their houses,” said Alfonso Verdu Perez, head of the ICRC delegation in Sudan.

Parts of Khartoum and Omdurman are still without water and electricity, with people sheltering indoors to avoid the constant shelling and air strikes. Everything is closed, including Khartoum airport, which has been badly damaged by shelling, leaving people without access to food. Stinking corpses lie uncollected in the streets. Italian NGO boss Stefano Rebora told the BBC, “There's utter destruction too. Everything is just devastated.'

Monitoring service NetBlocks said that Sudan experienced a “near-total collapse” of internet and phone services Sunday.

ICRC spokeswoman Alyona Synenko told the BBC the situation was now “untenable” for civilians left without food or water and some hospitals out of action. People were making “desperate attempts” to flee.

Around 10,000 Sudanese fled the country for South Sudan over the weekend, while at least 20,000 are believed to have crossed from the western Darfur region where fighting has flared up again into neighbouring Chad, which already hosts 400,000 Sudanese refugees. Many have fled the capital, home to 10 million people, for other parts of the country where they have family ties, leaving parts of the city centre completely deserted. Others have gone north to Egypt by bus or gone south.

The huge movement of people threatens to overwhelm Sudan’s seven neighbours, themselves wracked by poverty and instability and hosting refugees and internally displaced people.

Sudan itself hosts about 1.1 million refugees and asylum seekers, mostly from South Sudan, which seceded from Sudan in 2011 and has been ravaged by civil war ever since. Others have fled conflicts and autocratic rule in Eritrea, Ethiopia and Syria. Still more are migrants working in Sudan to support their families back home. The fighting will disrupt the flow of remittances and limit cross-border trade.

United Nations Secretary General Antonio Guterres warned that Sudan was “on the edge of an abyss,” as the brutal fighting between rival forces shows no sign of abating and that the violence in Sudan, one of the world's poorest countries, with a history of military coups, “could engulf the whole region and beyond.”

In the last days, the UN, United States and numerous European, Middle Eastern, African and Asian nations have launched emergency operations to evacuate their diplomatic staff and in some instances their nationals from the country by road, air and sea. Most sent military helicopters to Khartoum from the Red Sea state of Djibouti to fly people out amid a brief ceasefire, while others transported them in convoys the 500 miles to Port Sudan on the Red Sea.

With some of the convoys coming under attack, including one carrying Qatari embassy staff and another carrying French citizens, the situation is too dangerous to be able to evacuate more than a few foreign nationals.

Both leaders of the two rival factions now fighting for control of the country rose to prominence during the war in Darfur, in western Sudan, where 300,000 people were killed and 2.5 million were displaced in fighting from 2003 to 2008. Al-Burhan was an army chief, while Dagalo (widely known as Hemedti), led the notorious Janjaweed militias responsible for some of the worst atrocities of the conflict, with both men implicated in war crimes and crimes against humanity.

These corrupt figures are engaged in a conflict that has global impulses, origins and implications, with US imperialism playing the central role.

Al-Burhan is backed by Egypt’s brutal dictator, Abdel Fattah el-Sisi and layers close to the military that have long controlled Sudan’s sprawling military-industrial complex. He is supportive of the United States and the European powers in the US/NATO war against Russia in Ukraine.

Dagalo, who has become enormously rich based on Darfur’s gold, is backed by the United Arab Emirates (UAE) and Saudi Arabia. Controlling the export of gold, much of which goes to Russia via the UAE, he has close relations with Russia. Moscow, whose Wagner mercenaries operate in Sudan and neighbouring Central African Republic, is trying to establish a base at Port Sudan.

The US Biden administration, infuriated by Sudan’s abstention on the UN resolution condemning Russia’s invasion of Ukraine, has been determined to sever Sudan’s relationships with Iran, Russia and China; close Port Sudan to the Russian navy; and strengthen its regional anti-Iran alliance to which Sudan had signed up earlier this year. This meant curbing the military and its relations with Russia and encouraging Sudan’s transitional civilian government under Abdalla Hamdok to crack down on the military’s export of gold to Russia, which enabled Moscow to evade sanctions. This was one of the factors that led to the military’s coup against Hamdok’s government in October 2021, which US official and former official sources accuse Russia of backing. The anti-corruption committee leading the crackdown was then immediately dismantled.

The violence that erupted on April 15 came after weeks of mounting tensions, increased army deployment and security measures and jockeying by the rival factions for public and international support over the planned integration of the RSF and other former rebel militias involved in insurgencies in various parts of the country into the Sudanese army. This was a key demand of al-Burhan’s faction in the Framework negotiations aimed at forming a civilian-led government that would leave the military and its corporations in economic control, while ending the protests and social unrest that had engulfed the country since December 2018 and led to the military’s pre-emptive coup against long-time dictator Omar al-Bashir in April 2019.

Since then, Burhan and Hemedti have had increasingly fractious relations, amid a crackdown on the ongoing social protests that have led to the deaths of more than 120 civilians. Some 15 million of Sudan’s 46 million people already faced acute food insecurity due to escalating food and fuel prices, the economic crisis precipitated by the secession of oil-rich South Sudan in 2011, political instability, conflicts and the displacement of some 3 million people, poor harvests and floods.

Dagalo refused to integrate his RSF into the Sudanese army unless the military was placed under civilian control and the Islamists that had pulled the strings under al-Bashir were eliminated as a political force. This has enabled him to win support from some of the middle-class professional and civilian groups that are party to the negotiations and in December signed a renewed Framework agreement with the military for a return to civilian rule.