Representatives of the warring parties in Sudan are scheduled to hold a second round of talks in the Saudi coastal city of Jeddah on Sunday.
They will discuss how to implement plans to deliver humanitarian aid and remove troops from civilian areas, a senior Saudi diplomat said according to Reuters.
The parties will remain in Jeddah to start the next phase of the negotiations after agreeing on Thursday to the plan to protect civilians, the diplomat said on Saturday.
Khartoum residents described fierce battles on Saturday with fighters roving the streets and little sign the army and Rapid Support Forces (RSF) were respecting the Jeddah declaration.
Fighting has rocked Khartoum and adjoining areas as well as Geneina in the Darfur region since the warring forces agreed a "declaration of principles" on Thursday.
The conflict that broke out a month ago has killed hundreds of people, sent more than 200,000 into neighboring states, displaced another 700,000 inside the country, and risks drawing in outside powers and destabilizing the region.
Airspace will stay closed except for aid flights until May 31, authorities said on Saturday.
The two sides have battled through previous truces and have shown no sign of being willing to compromise. Although the RSF promised to uphold Thursday's agreement, the army has not yet commented on it.
Neither side seems able to secure a quick victory, with the army able to call on air power but the RSF dug into residential districts throughout the capital.