The RSF has been advancing through western and central areas in its eight-month-old war against Sudan's army and its approach on Wad Madani has caused thousands of people to flee. The city lies in an important agricultural region in a country facing worsening hunger.

There was no immediate comment from the army.

Videos posted by the RSF showed fighters in pick-up trucks driving along city streets and over a bridge across the Blue Nile.

In one video, RSF fighters carrying rifles stood with their arms around Coptic priests, who said they had not been able to flee but asked the RSF for help leaving the city.

The videos were not verified by Reuters.

The war between the army and the RSF has displaced nearly 7 million people, left the capital in ruins, caused a major humanitarian crisis and triggered waves of ethnically driven killings in Darfur.

The two forces had shared power with civilians after the 2019 overthrow of former leader Omar al-Bashir before staging a coup together in 2021 then coming to blows over an internationally backed political transition plan.

The International Organization for Migration says that clashes between the RSF and the army around Wad Madani have led to widespread displacement in recent days.

Nearly 1.5 million have fled Sudan and more than 5.4 million have been forced from their homes internally, according to the IOM, making Sudan the country with the highest number of displaced people in the world.

(Reporting by Khalid Abdelaziz and Nafisa EltahirWriting by Aidan LewisEditing by Tomasz Janowski and Christina Fincher)