Sudanese ex-official Ahmed Haroun, who served under Omar al-Bashir, said that he and other former officials of Bashir's government had left Kober prison.

Ahmed Haroun was the head of the ruling National Congress Party and among dozens of Sudanese officials who were arrested in 2019 following a popular uprising and military coup hat toppled the regime of former President Omar al-Bashir.

In a statement on Tuesday, Haroun, who is wanted by the International Criminal Court, also said they were ready to appear in front of the judiciary whenever it was functioning.

According to Haroun, they would take responsibility for their own protection.

The statement comes after reports that prisoners at Kober prison, which held Sudanese President Omar al-Bashir and other top deputies, had staged a break earlier this week.

It was not immediately clear if Bashir, who has spent extended periods in a military hospital, was at the prison.

Sudanese and foreigners fled Khartoum on Tuesday as fighting followed a three-day truce.

A series of short ceasefires in the past week have either failed or brought only short pauses in fighting between forces loyal to the country's two top generals since April 15.

At least 450 people, including civilians and fighters, have been killed, and more than 4,000 wounded in the fighting, the UN said, citing Sudan’s Health Ministry.

Aid agencies have warned over a humanitarian situation in a country reliant on outside help.

UN Secretary-General Antonio Guterres warned that the power struggle between rival generals and their military forces was not only putting Sudan's future at risk but it “lighting a fuse that could detonate across borders, causing immense suffering for years, and setting development back by decades”.

He urged the Sudanese military, commanded by Gen Abdel Fattah Burhan, and the rival Rapid Support Forces, a paramilitary group led by Gen Mohamed Dagalo, “to silence the guns” immediately.

On April 15, violent clashes between the Sudanese regular armed forces and the powerful RSF broke out, with the epicentre in Khartoum. The military accused the RSF of mutiny and launched airstrikes against their bases.