"The UN was taken by surprise" by the conflict, Secretary-General Guterres said.

A leading figure of the regime of the deposed ruler Omar al-Bashir has escaped jail.

The warring groups in Sudan continued to engage in fierce clashes on Friday with heavy gunfire and explosions heard in the capital Khartoum and other cities despite the proclamation of a 72-hour ceasefire.

Sudan's warring generals have agreed on a 24-hour truce, hours after the army bluntly rejected a call by rival paramilitary forces for the humanitarian ceasefire.