A drone attack on one of the last functioning hospitals in El-Fasher in Sudan's Darfur region killed 30 people and injured dozens, a medical source said Saturday.
The bombing of the Saudi Hospital on Friday evening "led to the destruction" of the hospital's emergency building, the source told AFP, requesting anonymity for fear of retaliation.
It was not immediately clear which of Sudan's warring sides had launched the attack.
Since April 2023, the Sudanese army has been at war with the paramilitary Rapid Support Forces (RSF), who have seized nearly the entire vast western region of Darfur.
They have besieged El-Fasher, the state capital of North Darfur, since May, but have not managed to claim the city, where army-aligned militias have repeatedly pushed them back.
Last week, they issued an ultimatum demanding army forces and allies leave the city by Wednesday afternoon in advance of an expected offensive.
Local activists have reported intermittent fighting since, including repeated artillery fire from the RSF on the famine-hit Abu Shouk displacement camp.
On Friday morning alone, heavy shelling killed eight people in the camp, according to civil society group the Darfur General Coordination of Camps for the Displaced and Refugees.
The United Nations has voiced alarm, calling on both parties to ensure the protection of the city's civilian population -- some two million people.
"The people of El-Fasher have suffered so much already from many months of senseless violence and brutal violations and abuses, particularly in the course of the prolonged siege of their city," United Nations rights office spokesman Seif Magango said Wednesday.
- RSF drones -
According to the medical source, the Saudi Hospital's emergency building had been hit by an RSF drone "a few weeks ago".
Between December 9 and January 14, Yale University's Humanitarian Research Lab observed three advanced drones at the RSF-controlled Nyala Airport, some 200 kilometres (124 miles) south.
In its report, it said the Chinese-made drones have "significant electronic surveillance and warfare capabilities and can be equipped with air-to-ground munitions", but could not verify which countries had purchased them.
The United Arab Emirates has been repeatedly accused of funnelling weapons, including drones, to the RSF.
United Nations experts determined in December 2023 the allegations were "credible", but Abu Dhabi has issued repeated denials in the face of mounting international criticism.
In December, it assured the outgoing administration of US president Joe Biden that it was "not now transferring any weapons" to the RSF.
The US concluded earlier this month that the paramilitaries were committing "genocide" in Darfur.
- Attacks on healthcare -
The RSF's latest attempt to consolidate its hold on war-ravaged Darfur -- a vast region about the size of France, home to a quarter of Sudan's population -- comes as the army claims significant victories elsewhere.
Some 800 kilometres (500 miles) east, the military on Friday regained control of a major oil refinery and broke a paramilitary siege on its Khartoum headquarters, which the RSF had encircled since the war began in April 2023.
Earlier this month, the army successfully wrested control of key state capital Wad Madani, just south of Khartoum, from the RSF.
Since the war began, both the army and the RSF have been accused of war crimes, including targeting civilians and indiscriminately shelling residential areas.
Before leaving office on Monday, the Biden administration sanctioned Sudanese army chief Abdel Fattah al-Burhan, accusing the army of attacking schools, markets and hospitals and using food deprivation as a weapon of war.
Across the country, up to 80 percent of healthcare facilities have been forced out of service, according to official figures.
In El-Fasher, where ambulances and hospital buildings have been routinely targeted, medical charity Doctors Without Borders said this month the Saudi Hospital was "the only public hospital with surgical capacity still standing".
The war has so far killed tens of thousands, uprooted more than 12 million and brought millions to the brink of mass starvation.
In the area around El-Fasher, famine has already taken hold in three displacement camps -- Zamzam, Abu Shouk and Al-Salam -- and is expected to expand to five more areas including the city itself by May, according to a UN-backed assessment.