About 90 people have been killed in new violence that threatens to divide the U.S. military’s partners in Syria in the fight against the Islamic State group.

Roughly 900 U.S. troops are deployed to Syria on a mission to prevent ISIS from reconstituting its caliphate, which was destroyed in 2019. America’s primary ally in the country has been the Syrian Democratic Forces, or SDF, a predominantly Kurdish organization that also includes Arab and Turkmen militias.

But the ties binding the anti-ISIS alliance began to fray after the SDF arrested the head of an Arab-majority militia on Aug. 27, leading to open fighting with Arab tribesmen in Syria’s Deir ez-Zor region.

At least 90 people have been killed in the fighting so far, according to the Syrian Observatory for Human Rights, a group based in Britain that documents human rights abuses in Syria.

Elsewhere in northeast Syria, the SDF has clashed with the Syrian National Army, or SNA – a different rebel group that is backed by Turkey – in Al-Hasakah province, leaving 23 people dead in a separate outbreak of violence.

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On Aug. 27, the SDF launched “Operation Security Reinforcement” in Deir ez-Zor, which it said targeted ISIS terrorist cells along with “criminals responsible for perpetrating injustices against the local population.”

U.S. and coalition forces were not involved with the operation, said Army Maj. Geoffrey Carmichael, a spokesman for Combined Joint Task Force – Operation Inherent Resolve, the U.S.-led alliance against ISIS in Iraq and Syria.

Syrian Democratic Forces
A fighter of the Syrian Democratic Forces (SDF) stands guard along a road as others deploy to impose a curfew in the town of al-Busayrah in Syria’s northeastern Deir ez-Zor province on September 4, 2023, during a guided media tour organised by the SDF (Delil Souleiman/AFP via Getty Images)

SDF spokesman Farhad Shami announced on Aug. 30 that Ahmed al-Khubail, also known as Abu Khawla, had been dismissed from his duties as head of the Deir ez-Zor Military Council “based on an arrest warrant from the Public Prosecution in North and East Syria.”

Shami accused Abu Khawla of being involved with drug trafficking and having a “negative role in increasing the activity of ISIS cells.”

On Tuesday, Shami downplayed the violence that erupted in Deir ez-Zor following Abu Khawla’s arrest.

“Out of 120 villages, only four experienced tension,” Shami told Task & Purpose on Tuesday. “After successfully clearing three villages of the intruding armed groups affiliated with the Syrian regime, we are now focused on decisively retaking Dhiban village.”

As of Tuesday afternoon, the SDF had retaken 80% of Dhiban, Shami tweeted on Tuesday.

Shami also accused the SNA of sending its Arab fighters to fight the SDF as part of a plan to allow Turkmen factions to consolidate their authority in parts of the country.   

Syria conflict
Syrian Arab fighters are positioned on the Mahsali and Arab Hasan frontline, on the Turkish-held outskirts of Manbij in northeastern Syria, as they fight with the Kurdish-led Syrian Democratic Forces on September 4, 2023. (Rami al Sayed/AFP via Getty Images)

Task & Purpose was unable to independently verify any of Shami’s comments on Tuesday.

Combined Joint Task Force – Operation Inherent Resolve has issued two statements since Aug. 31 calling for an immediate end to violence in northeast Syria, which it calls a distraction from the fight against ISIS.

Despite the violence, the U.S. military will continue to work with the SDF and other partners in Syria, Air Force Brig. Gen. Pat Ryder, a Pentagon spokesman, told reporters on Tuesday.

The SDF has played a critical role in the fight against ISIS, Ryder said at a Pentagon news briefing. Ryder noted that the SDF runs the al-Hol detention refugee camp, where the families of suspected ISIS fighters are held.

“Our work with the SDF is focused only on the defeat-ISIS mission,” Ryder said when asked if the U.S. military supports the SDF in the current power struggle.

Ryder declined to say whether or not the SDF gave the U.S. military advance notice before it arrested Abu Khawla.

When asked if the U.S. military is trying to moderate a solution between the SDF and Arab tribes, Ryder deferred the question to Combined Joint Task Force – Operation Inherent Resolve.

“You’ve heard us call for all parties to cease fighting and stay focused on the mission, because, again, the only winner here is ISIS,” Ryder said.

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