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, reports the Sudan Doctors' Network.
Most of the dead were part of the same family, the medical group added.
Although no group has claimed responsibility, medics allege that the paramilitary Rapid Support Forces (RSF) are to blame for the attack in an army-controlled area, which the RSF has been attempting to infiltrate for months.
As the civil war between Sudan's army and RSF rebels approaches its third anniversary, the severity of the suffering has led to the United Nations declaring the crisis as the world's worst humanitarian disaster.
To date, more than 11 million people have been displaced by the violence, with fatalities in the hundreds of thousands. Widespread sexual violence is being used as a weapon of war.
The RSF and the Sudanese Armed Forces stand accused of numerous atrocities.
Witness accounts suggest that the drone attack occurred in a residential neighborhood on Monday.
The Sudan Doctors' Network condemned the incident as a dangerous escalation of indiscriminate killing and systematic attacks on safe residential areas.
Despite RSF advances in the region, el-Obeid remains under army control.
Analysts indicate the city is strategically important to the RSF due to its location between Sudan's capital, Khartoum, and the Darfur region, where RSF has established a parallel government and faced accusations of genocide.
The attack follows recent RSF assaults, including one on a power plant in el-Obeid and attempts to target the largest hydroelectric dam in the country.
