KHARTOUM, May 20, 2025 (BSS/AFP) - Clashes erupted on Tuesday between the Sudanese regular army and the paramilitary Rapid Support Forces in Omdurman, Khartoum's twin city, the army said, calling the fighting part of a "large-scale" offensive.

Explosions rang out in the area, where the RSF had retreated after losing control of the Sudanese capital in March, an AFP correspondent at the scene reported.

The army said its operation was aimed at driving the paramilitaries, with which it has been at war since April 2023, from their last positions in Khartoum state.

"We are pressing a large-scale operation and we are close to clearing the whole of Khartoum state from dirty thugs," military spokesman Nabil Abdallah said in a statement.

The conflict has pitted the army headed by Sudan's de facto leader Abdel Fattah al-Burhan against the RSF under his former deputy Mohamed Hamdan Daglo.

In recent weeks, the RSF has staged multiple drone attacks on areas around the country, notably Port Sudan where the army is headquartered.

"The magnitude of these drone attacks represents a major escalation in the conflict, with alarming implications for civilian protection," the UN's human rights expert on Sudan Radhouane Nouicer said in a statement on Monday.

"The recurrent attacks on critical infrastructure place civilian lives at risk, worsen the humanitarian crisis, and undermine basic human rights."

Nouicer also said the drone attacks frequently targeted heavily populated areas and key infrastructure such as Port Sudan's airport.

- Split in two -

The war has sparked what the United Nations describes as the world's worst humanitarian crisis.

It has effectively split the country in two, with the army controlling the north, east, and centre, while the RSF dominates nearly all of Darfur and parts of the south.

Besides killing tens of thousands of people, the two-year conflict has uprooted 13 million others, more than three million of whom have fled the country as refugees.

Sudan's already fragile healthcare system has been pushed to "breaking point" by the war, according to the World Health Organization.

Up to 90 percent of the country's hospitals have at some point been forced to close because of the fighting, according to the doctors' union, with health facilities stormed, bombed and looted.

Women and girls in the country face gang rapes, sexual slavery and killings, particularly at the hands of the paramilitary forces, according to UN experts.