5.1.3. ISIL

Since the fall of the Assad regime in December 2024, ISIL activity in Syria has sharply declined,759 largely due to sustained aerial operations by the US-led International Coalition and declining recruitment appeal.760 According to military sources of the U.S-led coalition, ISIL has shown no notable improvement in its operational capabilities or attack sophistication in Syria during January-March 2025. However, the U.S. Defense Intelligence Agency (DIA) warned that the group continued to opportunistically exploit the volatile security landscape following the fall of the Assad regime.761

U.S. sources assessed that ISIL activity in March 2025 shifted westward compared to earlier in the first quarter of 2025, with cells continuing to operate from caves and isolated areas in the Badiya desert, particularly in Homs governorate.762

Despite a decline in attacks in the previous period, ISIL has steadily increased its attacks on the SDF, reaching a monthly peak in April 2025 with 10 recorded incidents. This uptick coincided with growing concerns over the security of detention facilities housing ISIL fighters in the northeast, as funding for their maintenance and staffing become uncertain. Several attempted prison breaks have recently been thwarted.763 According to expert on Sunni Arab jihadi groups Aaron Zelin, by mid-May ISIL claimed 33 attacks in 2025.764 While most ISIL attacks have targeted the SDF765 and civilians766 in the northeast, the group has also escalated its rhetoric against authorities in Damascus, although only a limited number of attacks have been directed at GSS or MoD units.767 ISIL has reportedly sought to exploit dissatisfaction with the Syrian transitional government among HTS Salafi-jihadi hardliners by attacking al-Sharaa and calling on HTS members to defect and join the terrorist organisation.768

In May, an ISIL vehicle-borne improvised explosive device (VBIED) attack on a GSS post in Mayadin, Deir Ez-Zor, killed at least four security personnel and one civilian. Meanwhile, a security operation targeting ISIL cells in Aleppo city resulted in the deaths of two ISIL fighters and two GSS members.769

SDF arrested 13 ISIL cells in Raqqa, Hasaka and Deir Ez-Zor governorates as of March 2025 while U.S. carried out airstrikes on ISIL targets.770 In May, it was reported that two alleged ISIL members accused of killing a MoD officer were arrested GSS forces in Idlib and reportedly executed.771 ISIL activity increased in May, partly due to cells seizing of weapons stocks of the former regime, recruitment of regime remnants. Three large scale anti-ISIL raids were carried out in May by government forces in Deir Ez Zor, Aleppo and Rural Damascus governorates.772 On 22 June, a suicide bomber with apparent ties to ISIL attacked the Greek Orthodox Church in Dweila neighbourhood of Damascus leaving at least 22 persons killed and 63 wounded.773

Around 9 000 male ISIL suspects are detained without due process in northeast Syria, including 5 400 Syrians, 1 600 Iraqis, and some 1 500 from 50 other countries. The vast majority of these detainees continue to be held incommunicado without information on their fate or whereabouts, according to UN experts. In addition, some 42 500 individuals, the majority of whom are children, are arbitrarily held in camps, including family members and ISIL associates. Many have been held without legal process for at least six years.774 Amnesty International noted that Syrians and Iraqis make up to 80 % of the population in al-Hol camp. As of March 2025, Iraq repatriated over 5 600 individuals from al-Hol camp.775 In May, the DAANES and the transitional government reached an agreement to create a joint mechanism for the return of Syrian families from the al-Hol camp.776 In June, several families of Syrians from the camp had reportedly been returned to their areas of origin in northwest Syria777 and more than 800 Iraqis had been repatriated.778