In this Monday, Oct. 7, 2019 file photo, a fighter from the U.S.-backed Kurdish-led Syrian Democratic Forces (SDF)  stands guard inside a post where U.S. troops were based, in Tal Abyad town, at the Syrian-Turkish border, Syria.
In this Oct. 7, 2019 file photo, a fighter from the U.S.-backed Kurdish-led Syrian Democratic Forces, SDF, stands guard inside a post where U.S. troops were based, in Tal Abyad town, at the Syrian-Turkish border, Syria.

WASHINGTON - U.S.-backed forces have intensified their campaign against the remnants of the Islamic State (IS) terror group in eastern Syria.

The Syrian Democratic Forces (SDF), a military alliance that has been a major U.S. partner in the fight against IS, said it has captured dozens of IS members in the eastern Syrian province of Deir el-Zour.

“Our forces have already arrested over 30 terrorists,” said Siyamend Ali, a press officer with the People’s Protection Units (YPG), the main element within SDF.

“This ongoing campaign is targeting (IS) hideouts and underground tunnels that have been instrumental in their recent insurgency,” he told VOA in a phone interview.

The SDF said in a statement last week that its latest campaign was in retaliation for the recent killing of two female officials by IS, adding that the “large-scale operation” targets the terror group “across the entire Deir el-Zour desert and along the Syrian-Iraqi border.”

Seda al-Faisal al-Hermas and Hind Latif al-Khidr, two local leaders in eastern Syria, were reportedly kidnapped and killed by IS militants in late January. The United States has condemned the killings.

FILE - In this Feb. 22, 2019 file photo, U.S.-backed Syrian Democratic Forces (SDF) fighters stand guard next to men waiting to be screened after being evacuated out of the last territory held by IS militants, near Baghouz, eastern Syria.

Despite its territorial defeat in March 2019, IS continues to pose a threat in eastern Syria. In recent weeks, the militants have escalated their attacks against civilians and SDF-affiliated personnel, particularly in Deir el-Zour and Hasaka provinces.

Several Arab tribal leaders and civil servants have been killed in recent attacks claimed by IS.

“There is a need for us to intensify the operations, especially after the organization started to expand its attacks to the Syrian Badia (desert) and its attempts to expand to regions that were liberated by our forces,” Mazloum Abdi, general commander of the SDF, said last week in an interview with the pan-Arab Asharq al-Awsat newspaper.

U.S. military officials said the global coalition against Islamic State is committed to assisting its SDF partners in its ongoing anti-IS operations.

“The coalition provides our SDF partners with a number of enabling capabilities, to include intelligence, surveillance and reconnaissance, air power when requested, and logistics,” Col. Wayne Marotto, spokesman for the U.S.-led coalition, told VOA.

The militant group has also increased attacks and ambushes against Syrian government forces and its allied militias in areas such as Deir el-Zour, Homs and Hama.

In January, IS militants carried out at least 46 attacks in central Syria, killing at least 55 pro-Syrian government fighters and 26 civilians, according to the Counter Extremism Project.

Experts say while IS currently has no capability to hold territory in Syria or Iraq, the extremist group will likely continue to wage major attacks against other forces in both countries.

“The challenge in Syria is the fact that the country is fragmented because of the civil war, and this means there is no unified effort to counter IS,” said Sadradeen Kinno, a Syrian researcher who focuses on Islamist militancy.

IS militants “have been exploiting this political and territorial fragmentation to make gains across the country,” Kinno told VOA.