Renewed artillery exchanges rocked greater Khartoum early Wednesday as Sudan's rival generals resumed fighting just minutes after the latest US and Saudi-brokered ceasefire expired.

Already on Tuesday evening, an immense blaze had engulfed the intelligence service's headquarters in the capital Khartoum with each side blaming the other for attacking it in violation of the 72-hour truce.

A source within the regular army, led by Abdel Fattah Al-Burhan, accused rival paramilitaries loyal to his former deputy Mohammed Hamdan Dagalo of targeting the building.

Meanwhile, a source within the paramilitary Rapid Support Forces said an "army drone bombed the building where RSF fighters had gathered, sparking a fire and the partial destruction of the intelligence headquarters."

On Wednesday morning, residents of Omdurman, just across the Nile from Khartoum, reported heavy fire exchanges within minutes of the ceasefire expiring at 6:00 am (0400 GMT).

Witnesses also reported that army warplanes flew low over several adjacent districts.

The millions of people caught by the conflict in greater Khartoum saw a little reprieve thanks to the truce, which was timed to coincide with an international donors' summit in Geneva on Monday. However, an exodus of refugees continued to flood out of Darfur, the war's other key frontline.

On its part, the Armed Conflict Location and Event Data Project reported that more than 2,000 people have been killed since the clashes between Burhan and Daglo erupted into fighting on April 15.

More than 2.5 million people have fled their homes, of whom around 550,000 have sought refuge in neighboring countries, or fled abroad, as per the International Organization for Migration.

Streets filled with bodies

The West Darfur state capital El Geneina alone has seen up to 1,100 fatalities, according to the US State Department.

Bodies have filled the streets of the city, where months of unrest have left shops either vacant or gutted by looters.

Thousands of locals have fled, grabbing everything they could to get to the Chad border. Since the start of the violence, at least 150,000 people have fled from Darfur into Chad, according to the UN.

Nearly $1.5 billion in aid pledges were received for Sudan and its neighbors at the donors' meeting on Monday, but the organizers said that just half of the anticipated needs had been met.

A record 25 million people -- more than half of Sudan's population -- are in need of aid and protection, as per the United Nations.

UN chief Antonio Guterres warned, "The scale and speed of Sudan's descent into death and destruction is unprecedented."

Read next: Sudan: A borderless conflict