A network of Colombian mercenaries backed by the United Arab Emirates (UAE) provided critical support to Sudan’s paramilitary Rapid Support Forces (RSF), enabling it to capture the western city of el-Fasher last year, a new report says. The UAE has long denied supporting the RSF, which has been fighting Sudan’s regular army for three years.

El-Fasher’s Fall and the Humanitarian Crisis

El-Fasher’s fall was one of the most harsh chapters of the conflict, which has led to the world’s worst humanitarian crisis with tens of thousands killed and millions forced from their homes. The CIG has been closely following evidence of extensive Emirati military assistance to the RSF, but “this is the first research where we can prove UAE involvement with certainty,” says director Justin Lynch.

“We are making public what governments have long known – that there is a direct link between Abu Dhabi and the RSF.” The report “shows mercenaries involved with drones travelling from a UAE base to Sudan before the RSF takeover of el-Fasher,” he says. “Mercenaries involved in drone operations even named their wi-fi network their unit name – linked to a company operated out of the UAE.”

Tracking Colombian Mercenaries in Sudan

The CIG says it used commercially available technology designed to make advertising more personal to track more than 50 mobile phones in Sudan between April 2025 and January this year whose operators were Colombian mercenaries, including at RSF-held areas from which drones were fired. It also used flight-tracking data. Satellite imagery, social media videos, news and academic articles to support its analysis.

The report says its data details a pipeline that showed the mercenaries present at various regional staging grounds, most significantly a UAE military training facility in Ghayathi in Abu Dhabi. It followed one phone from Colombia to Abu Dhabi’s Zayad International Airport and then to the facility, where it also found four other devices configured to Spanish, which is spoken in Colombia.

Two of those phones subsequently travelled to Sudan’s South Darfur state and one to the de-facto RSF capital of Nyala, where it logged into wi-fi networks named “ANTIAEREO” (meaning “anti-aircraft” in Spanish) and “AirDefense.” Nyala is a prominent hub for Colombian mercenaries and RSF drone operations, the report says. The CIG has documented significant drone activity there and identified more than 40 Spanish-language devices.

Controversy and International Response

In another case study the CIG tracked a phone from Colombia to Nyala and then to el-Fasher, in North Darfur state, during the time last October when the RSF took over the city after an 18-month siege. While in el-Fasher. The device connected to a wi-fi network named “ATACADOR” (“attacker” in Spanish), says the report; it adds that the CIG identified other devices associated with Colombian mercenaries also present during the RSF takeover.

The fall of the city was accompanied by mass atrocities assessed as war crimes and crimes against humanity by the prosecutor of the International Criminal Court (ICC) and described by UN investigators as bearing the “hallmarks of genocide.” “CIG assesses that the UAE-Colombian mercenary network bears shared responsibility for these outcomes,” says the report. “The scale of atrocities and siege in el-Fasher wouldn’t have happened without the drone operations the mercenaries provided,” Lynch adds, noting evidence that they also helped support the RSF siege.