The RSF, at war with the army for two years, used "long-range artillery" launched from their holdout position in al-Salha, located south of Khartoum's twin city of Omdurman, the source told AFP on condition of anonymity.

There were no immediate reports of casualties.

On Saturday, the RSF targeted the army's General Command headquarters in central Khartoum, also using long-range artillery fire, according to a military source.

The attacks come weeks after the army pushed the RSF out of central Khartoum, which the paramilitary had swept through early in the war.

In a major military offensive in March, army forces regained control of the presidential palace, the airport and other strategic areas in the capital.

But the RSF still clings to its last pockets of control in southern and western Omdurman.

Since April 2023, the war in Sudan has killed tens of thousands, uprooted 13 million and created the world's largest hunger and displacement crises.

The conflict has effectively divided the country in two with the army holding the centre, east and north while the RSF controls nearly all of Darfur and parts of the south.