Khartoum residents reported a welcome lull in fighting in Sudan's capital on Saturday after a 24-hour ceasefire between two warring generals took effect, but few believed it would hold.

"Since the war started, this is the first time hours go by and we don't hear the sound of guns," said Hamed Ibrahim, adding that "today was completely different" in his east Khartoum neighbourhood.

Fighting has raged in the country since mid-April, when army chief Abdel Fattah al-Burhan and his former deputy Mohamed Hamdan Daglo, who commands the paramilitary Rapid Support Forces (RSF), turned on each other.

Multiple truces have been agreed and broken since the conflict flared, and Washington slapped sanctions on both rival generals after the last attempt collapsed at the end of May.

This latest truce is due to expire at 6:00 am (0400 GMT) on Sunday.

The air strikes and artillery bombardments that have rocked greater Khartoum almost daily subsided at least temporarily on Saturday, allowing trapped civilians to venture outdoors to buy desperately needed supplies.

"Today we have witnessed a total calm," said Othman Hamed, a resident of the capital's sister city Omdurman, just across the Nile.

In one Khartoum market, people were seen scrambling to stock up on fruit and other basic goods.

"The truce is a chance for us to get some food supplies after we lived on rationed quantities in recent days," said one of the shoppers, Mohamad Radwan.

Hajar Youssef said she had gone out in search of an open pharmacy to buy insulin for her mother, who has diabetes. "Unfortunately, I did not find one."