US Secretary of State Marco Rubio has called for international action to cut off weapons supplies to Sudan’s paramilitary Rapid Support Forces (RSF), following reports of mass killings in el-Fasher.

At the end of a G7 foreign ministers meeting in Canada, Rubio said the RSF had committed systematic atrocities, including murder, rape and sexual violence against civilians.

Sudan’s army accuses the United Arab Emirates of supporting the group with weapons and mercenaries sent via African nations. The UAE has repeatedly denied the allegations.

The RSF has been fighting the Sudanese army since April 2023, when a power struggle between their leaders erupted into a civil war.

El-Fasher was captured last month by the RSF after an 18-month siege, meaning they now control all of the cities in the western Darfur region.

At the talks near Niagara Falls, America’s top diplomat said women and children had been targeted in acts of the most horrific kind by the RSF in el-Fasher.

Rubio told reporters: “They’re committing acts of sexual violence and atrocities, just horrifying atrocities, against women, children, innocent civilians of the most horrific kind. And it needs to end immediately.

“And we’re going to do everything we can to bring it to an end, and we’ve encouraged partner nations to join us in this fight.”

The secretary of state rejected the paramilitary group’s attempt to blame the killings on rogue elements, saying this was false and the attacks were systematic.

Asked by the BBC about his assessment of the likely scale of atrocities, he said the US feared that thousands of people who had been expected to flee el-Fasher were either dead or too malnourished to move.

He said the RSF, lacking its own arms manufacturing facilities, relied on outside support, and called for countries supplying weapons to stop.

The joint G7 statement also condemned surging violence in Sudan, saying the conflict between the army and the RSF had triggered “the world’s largest humanitarian crisis”.