The Doctors Without Borders medical charity said on Friday that armed men had attacked one of its teams in the Sudanese capital Khartoum while transporting medical supplies to a hospital.
The incident has put its continued activities at the hospital in doubt, said the organisation.
The 18-member team was attacked on Thursday while trying to reach the Turkish Hospital in the south of the city.
Khartoum has been gripped by unrest since fighting broke out on April 15 between the army and the paramilitary Rapid Support Forces.
“After arguing about the reasons for MSF's presence, the armed men then aggressively assaulted our team, physically beating and whipping them, as well as detaining the driver of one of our vehicles,” the Geneva-based organisation said in a statement.
“The armed men threatened the driver's life before releasing him. They then stole the vehicle.”
The incident happened 700 metres from the Turkish Hospital, which, said MSF, on the same day received 44 patients wounded in an air strike.
MSF said that its activities in the hospital, one of only two still open in southern Khartoum, were now in serious jeopardy and would not be able to be continued without minimum safety guarantees.
“If an incident like this happens again, and if our ability to move supplies continues to be obstructed, then, regrettably, our presence in the Turkish Hospital will soon become untenable,” said Christophe Garnier, MSF's emergencies manager for Sudan.
On Thursday, air strikes, street battles and artillery fire shook Khartoum, witnesses told AFP, reporting three air raids in the south in the early morning.
The Sudanese army, led by Gen Abdel Fattah Al Burhan, has been battling the RSF, commanded by his former deputy Gen Mohamed Dagalo, after the two fell out in a power struggle.
The fighting has killed at least 3,000 and forced more than 3.3 million to flee their homes.
MSF said it has treated more than 1,600 war-wounded patients in Khartoum since the conflict began.
The World Health Organisation has verified 51 attacks on healthcare centres in Sudan since the conflict began, resulting in 10 deaths and 24 injuries.
