The warring military factions in Sudan have accused each other of violating the latest temporary ceasefire.
The Sudanese army said the paramilitary Rapid Support Forces (RSF) had carried out an attack in North Darfur for a second consecutive day.
On Monday, the Red Cross said the ceasefire was not being respected and they had had to abort an operation to transfer wounded soldiers to a hospital.
Earlier, residents in the capital, Khartoum, reported a lull in fighting, saying they had heard no air strikes, artillery or other fighting there.
US and Saudi mediators had announced the 72-hour truce on Saturday. Previous truces have been poorly observed.