At least 13 people have been killed - eight of them children - after a drone strike on a house in the Sudanese city of el-Obeid, says the Sudan Doctors' Network.
Most of the dead were part of the same family, the medical group added.
Although no group has claimed responsibility, the medics say the paramilitary Rapid Support Forces (RSF) carried out the attack in an area controlled by the army, which it has been trying to penetrate for months.
As the civil war between Sudan's army and RSF rebels approaches its third year, the scale of suffering has prompted the UN and aid agencies to label it as the world's worst humanitarian crisis.
To date, more than 11 million people have been displaced by the violence, and hundreds of thousands have been killed, with widespread sexual violence being reported as a weapon of war.
Witnesses reported that Monday's drone attack occurred in a residential neighborhood, which the Sudan Doctors' Network stated reflects a dangerous escalation in the policy of indiscriminate killings and systematic bombings of safe areas.
Despite RSF's advancement in other regions, el-Obeid remains under army control, and analysts consider it strategically important given its location between Khartoum and the Darfur region, where the RSF has established a parallel government and faces accusations of genocide.
This incident follows recent attacks by the RSF on a power plant in el-Obeid and an alleged attempted strike on the country's largest hydroelectric dam.
