People gathered to flee during clashes between the RSF and the army in Khartoum, Sudan, on April 26, 2023 (Reuters)

Sudanese doctors' union confirmed on Tuesday that the civilian death toll has reached 447 and injuries have topped 2,255 since the conflict broke out on April 15.

On social media, the union posted: "The number of civilian deaths has increased to 447, and the number of injured to 2,255 since the clashes broke out".

This comes after UN Spokesperson Stephane Dujarric confirmed on Monday that UN Secretary-General Antonio Guterres has spoken to both Sudanese rival generals over the phone "at different times" and that "he will do whatever needs to be done."

He added that Guterres has the phone "glued to his ear" amid warnings that more than 800,000 people could flee fighting in Sudan, where gun battles and explosions again shook the capital in violation of the latest truce agreed between the warring generals.

According to the Ministry of Foreign Affairs of South Sudan, a truce was agreed upon from May 4 to May 11 on Tuesday by the leaders of the Sudanese military and the Rapid Support Forces (RSF).

In a social media post, the ministry said: "The two principals, H.E. Gen. Abdel Fatah Al Burhan, the Chairman of the Sovereign Council and Commander in Chief of Sudan Armed Forces (SAF), and Gen. Mohamed Hamdan Dagalo Leader of the Rapid Support Forces (RSF), have agreed in principle for a seven-day truce from May 4th to 11th".

South Sudan's Acting Foreign Minister, Deng Dau Malek, confirmed last Wednesday that Sudan's army chief Abdel Fattah al-Burhan has agreed to speak with the RSF General Mohamed Hamdan Daglo or Hemedti, but no location has been specified.

The chaos and bloodshed, now in their third week, have sparked a mass exodus of tens of thousands of Sudanese to neighboring countries including Egypt, Chad, and the Central African Republic. Millions of Sudanese around the capital and beyond have sheltered in their homes with dwindling food and water and frequent power cuts.

"Warplanes are flying over southern Khartoum and anti-aircraft guns are firing at them," said one resident, while another witness told AFP that he was also hearing "loud gunfire".

Top UN humanitarian official Martin Griffiths was heading to the region to help bring relief to the millions "whose lives have turned upside down overnight."

"The humanitarian situation is reaching breaking point," Dujarric warned.