ERBIL, Kurdistan Region of Iraq - Kurdish-led Syrian Democratic Forces (SDF) announced late Thursday that the Islamic State (ISIS) has seized a significant amount of territory in the desert areas of Homs and Deir Ezzor provinces, warning of the extremist group’s resurgence in areas they had once controlled prior to their territorial defeat in 2019, in the wake of a major rebel offensive launched last week. 

“The terrorist organization ISIS has recently declared control over significant portions of the Homs and Deer Ezzor desert, seizing numerous cities and strategic positions from the Damascus government forces,” the SDF announced in a statement posted on social media platform X. “Our SDF forces are taking effective measures to stop the expansion of ISIS.”

The rebels led by Hayat Tahrir al-Sham (HTS) launched a major offensive more than a week ago, rapidly seizing the strategic cities of Aleppo and Hama from government control. 

A war monitor reported on Friday that rebel fighters began advancing towards the country's third city Homs, despite the Damascus government taking measures to slow the rebel advance by targeting a key bridge on the highway linking the cities of Hama and Homs. 

Rebels led by HTS have now "entered the cities of Rastan and Talbisseh" on the main road from the strategic central city of Hama to Homs, said the Syrian Observatory for Human Rights (SOHR), adding the rebels were just five kilometers from Homs. 

The SDF warned that the rebel offensive could pave the way for the “expansion” of ISIS. 

“As the terrorist organization tries to continue its expansion to other unprotected areas, our forces have implemented comprehensive and controlled measures to counter these threats,” the US-backed force added. 

The extremist ISIS group was territorially defeated at the hands of Kurdish-led forces in 2019. The group, however, maintains a presence in the remote areas of both Syria and Iraq.

In a report published by SOHR in June to mark the 10th anniversary of the declaration of the so-called ISIS caliphate, the war monitor reported that ISIS remnants had killed around 4100 people in over 2,550 attacks in Syria since 2019, despite intense security operations conducted by the SDF.

ISIS took control of swathes of Syrian and Iraqi territory in 2014, announcing their self-proclaimed caliphate with the city of Mosul as its capital. They were territorially defeated with assistance from the US-led coalition forces in Iraq by 2017 and in Syria by 2019.