Hundreds of people have been killed and thousands wounded since a long-simmering power struggle between the Sudanese army and the paramilitary Rapid Support Forces (RSF) erupted into conflict on April 15.
Violence has rocked the capital Khartoum and risks reawakening war in the vast Western region of Darfur scarred by a two-decade old conflict, despite numerous ceasefire pledges.
Together, the army and RSF toppled a civilian government in an October 2021 coup but are now locked in a power struggle that has derailed an internationally backed transition to democracy and is threatening to destabilise a fragile region.
Both sides on Monday said a formal ceasefire agreement which was due to expire at midnight would be extended for a further 72 hours, in a move the RSF said was "in response to international, regional and local calls".
The army said it hoped what it called the "rebels" would abide by the deal but it believed they had intended to keep up attacks.
At least 528 people have been killed and 4599 wounded, the health ministry said. The UN has reported a similar number of dead but believes the real toll is much higher.
Many fear for their lives as Sudan's two most powerful men prosecute war in a country that has faced civil wars, coups and economic hardship for decades.
The fighting has pitched Sudan towards a civil war, derailing an internationally-backed transition aimed at establishing a democratic government and sending tens of thousands of people fleeing into neighbouring countries.
It has also deepened the humanitarian crisis in Sudan, where a third of the people were dependent on some form of humanitarian assistance before the fighting erupted, said Martin Griffiths, Under-Secretary-General for Humanitarian Affairs and Emergency Relief Coordinator at the UN.
"The scale and speed of what is unfolding in Sudan is unprecedented. We are extremely concerned by the immediate as well as long-term impact on all people in Sudan and the broader region," he said.
Army leader General Abdel Fattah al-Burhan has said he would never sit down with RSF chief General Mohamed Hamdan Dagalo, also known as Hemedti, who in turn said he would talk only after the army ceased hostilities.
In Khartoum, the army has been battling RSF forces entrenched in residential areas. Fighting has so far seen the more agile RSF forces fan out across the city as the better equipped army tries to target them largely by using air strikes from drones and fighter jets.
The conflict has sent tens of thousands of people fleeing across Sudan's borders and prompted warnings the country could disintegrate, destabilising a volatile region and prompting foreign governments to scramble to evacuate their nationals.
