At least three children were among five killed Tuesday when a drone attack hit the Sudanese town of Dilling, local medical sources confirmed.

Several drones fell on the town in the South Kordofan region, according to residents. At least 13 injured were taken to the Dilling hospital, a source at the hospital said.

Sudan's regular army, which has been fighting the paramilitary Rapid Support Forces (RSF) in the three-year civil war, retook Dilling in January after routing the RSF.

The Foreign Ministry Tuesday condemned "systematic attacks" on civilian homes and infrastructure by the RSF in Dilling and the North Kordofan capital of el Obeid and Kosti in White Nile state.

After taking the key city of el-Fasher in Darfur amid bitter fighting, the RSF has been concentrating its attacks on the army in Kordofan.

Sudan's civil war has left tens of thousands dead and more than 11 million displaced.

'RSF a terrorist group'

Also Tuesday, Sudan's Foreign Ministry said that the United States should designate the paramilitary RSF a "terrorist organization," a day after Washington slapped the same designation on the local branch of the Muslim Brotherhood.

The U.S. designation for the Brotherhood, which will come into effect next week, accused the group of receiving support from Iran.

Noting that decision, while stopping short of criticizing it, Sudan's Foreign Ministry said "all groups that violate international humanitarian law and commit terrorism, crimes against humanity, and war crimes in Sudan should be designated as terrorist groups."

The U.S., it added, should therefore "designate the RSF militia as a terrorist group, given its proven crimes and documented violations of international humanitarian law, including war crimes, crimes against humanity, genocide, and terrorism."