Air attacks on civilian gold diggers in a Sudanese border area killed at least 72 people on Saturday, the rights organization Emergency Lawyers said.
It warned that the toll was preliminary and might increase.
The group said aircraft struck camps used by informal miners at a well-known extraction site.
Egypt’s government and Sudan’s de facto authorities had not publicly addressed the reported strikes.
Emergency Lawyers said the incident echoed earlier accusations of Egyptian attacks on mining communities near the frontier.
The organization described the strikes as an infringement of Sudanese territory and a sign that the authorities could not secure the area.
It said attacks on civilians could breach international humanitarian law and potentially amount to war crimes.
The Paris-based Sudan Tribune reported that the number of victims may be higher. Citing a survivor, it said numerous people were wounded.
Witnesses told the newspaper that the assault began at about 6 a.m. local time, when aircraft launched more than five missiles at mining camps.
The strikes reportedly destroyed shelters and excavation sites while people were inside.
In June, the newspaper carried allegations that Egyptian forces had deployed drones and artillery against informal mining locations in the same area, killing several people.
It also reported earlier incidents in which Egyptian border guards allegedly burned equipment and temporary shelters and fired live rounds to drive workers away.
Several days later, Egypt’s border agency said it had launched a broad security operation with the military to combat unauthorized migration, narcotics trafficking and illegal mining.
Sudan’s de facto leader subsequently ordered an inquiry into earlier alleged air attacks, which were reported to have killed dozens.
Gold is a key source of tension along the frontier. Sudan’s civil war has contributed to a rise in informal mining, particularly in isolated border districts.
The work is often conducted without official authorization, using basic equipment and under hazardous conditions.
The mineral-rich frontier crosses remote terrain long associated with smuggling. Sudanese gold may enter those networks, while reports that mining continues in conflict areas have raised concerns that proceeds could help fund armed groups.
Egypt’s border force said in June that it had confiscated 86 tonnes of gold ore, along with equipment used for small-scale prospecting.
The trade has also prompted fears that illicit Sudanese gold could disrupt Egypt’s legal market.
By: Magdalene Agyeiwaa Sarpong