Sudan's Rapid Support Forces bombarded El-Obeid on Friday, killing six people in a hospital in the key southern city, medical and army sources said.

"The militia launched a drone strike on the Social Insurance Hospital, killing six and wounding 12, simultaneously attacking residential areas of the city with heavy artillery," an army source told AFP, adding that the bombardment had also hit a second hospital in the city center.

A medical source at El-Obeid Hospital, the city's main facility, confirmed the toll, adding that the Social Insurance Hospital had been forced shut "due to damage" sustained in the drone strike.

El-Obeid, a strategic city 400 kilometres (250 miles) southwest of Khartoum which is the capital of North Kordofan state, was besieged by the RSF for nearly two years before the regular army broke the siege in February.

It was one of a series of counteroffensives that also saw the army recapture Khartoum, but El-Obeid has continued to come under RSF bombardment.

The city is a key staging post on the army's supply route to the west, where the besieged city of El-Fasher is the only state capital in the vast Darfur region still under its control.

The RSF and the army have clashed repeatedly along the road between El-Obeid and El-Fasher in recent weeks.

On Thursday, the RSF said they retaken the town of Al-Khoei, around 100 kilometres (60 miles) west of El-Obeid, after the army recaptured it earlier this month.

The war between army chief Abdel Fattah al-Burhan and his former deputy, RSF commander Mohamed Hamdan Daglo, has killed tens of thousands of people and uprooted 13 million since it erupted in April 2023.

The United Nation says the conflict has created the world's biggest hunger and displacement crises.

It has also effectively split Sudan in two, with the army holding the centre, east and north, while the RSF forces and their allies control nearly all of Darfur and parts of the south.

Since losing Khartoum in March, the RSF has adopted a two-prong strategy: long-range drone strikes on army-held cities accompanied by a counteroffensive in the south.

On Thursday, the RSF also announced they had recaptured Dibeibat, in South Kordofan state some 100 kilometres (60 miles) south of El-Obeid, another town that the army had retaken earlier this month.

Swathes of South Kordofan are controlled by a rebel group allied with the RSF, Abdelaziz al-Hilu's faction of the Sudan People's Liberation Movement-North.