The Central Bank of Sudan branch is shown on video on fire as rioting rages on throughout Khartoum.
Despite a truce intended to allow residents to evacuate, airstrikes increased in the city on Sunday. The army said it was attacking the city to flush out its paramilitary rivals, the Rapid Support Forces (RSF).
Even when the warring parties announced they would prolong the ceasefire by a further three days, the violence got worse.
The actual number of casualties is thought to be substantially higher than the stated 500 dead. Many people are still stranded in Khartoum.
Gen. Abdel Fattah al-Burhan, the commander of the army, and Gen. Mohamed Hamdan Dagalo, often known as Hemedti, the head of the RSF, are competing for control. They clash particularly over proposals to integrate the RSF into the army.
Following intensive diplomatic efforts by neighboring nations, the US, UK, and UN, the generals decided on a humanitarian ceasefire. Despite being extended, it failed to hold.
However, it remains unclear on what they will do in the next stage of the deal arrived at with US and Saudi mediation, according to the army.
Before the announcement of the extension on Sunday, the army said it had conducted operations against RSF troops north of the city centre.
The first major aid flight, laden with medical supplies, has arrived in the country.
The International Committee of the Red Cross (ICRC) says a plane landed at Port Sudan with eight tonnes of relief supplies, including health kits for hospitals.