Sarah El Deeb

BEIRUT: Rebels backed by Turkey made major gains Sunday in northern Syria, expelling Kurdish-led forces from towns and villages as part of a determined campaign by Ankara to push the militants east of the Euphrates River.

At least 35 civilians were killed, according to activists. The dramatic escalation of Turkey’s involvement in the Syrian civil war last week aimed to help the Syrian rebels drive the Islamic State group out of the border town of Jarablus. But it also is aimed at U.S.-allied Kurdish forces that have gained control in recent months of most of the territory along the Turkey-Syria border.

The fighting pits Turkey, a NATO ally, against a U.S.-backed proxy that is the most effective ground force battling IS militants in Syria in the 5-year-old civil war. It leaves Washington in the tough spot of having to choose between two of its allied forces, and is likely to divert resources from the fight against IS.

A Turkish soldier was killed by a Kurdish rocket attack late Saturday, the first such fatality in Turkey’s ground offensive dubbed Euphrates Shield that began Aug. 24.

Speaking at a rally in the town of Gaziantep, Turkish President Recep Tayyip Erdogan said his military is committed to fighting terrorism in Syria and Iraq.

Turkey, he said, also is determined to “uproot” the Syrian Kurdish group, calling it a terrorist organization. But he didn’t specify a goal for the fight against the Kurdish forces.

Turkey is part of the U.S.-led coalition fighting the militants of the Islamic State group, but the airstrikes that began Saturday marked the first time it has targeted Kurdish-led forces in Syria.

“We will support all work to clean Syria and Iraq of Daesh,” Erdogan told the rally, using an Arabic acronym for the IS group. “That’s why we are in Jarablus, that’s why we are in Bashiqa [in Iraq]. If necessary, we will not shy away from taking responsibility in the same way in other areas.”

Turkey has troops stationed in Bashiqa in Iraq, and it was not clear if his reference to Jarablus means he intends to base his troops there.

Erdogan then turned his focus to the main Syrian Kurdish Democratic Union Party, known as the PYD.

“We are as determined about the PYD, the separatist terror organization’s Syrian wing,” he said. Ankara views the PYD and the militia affiliated with it, which forms the backbone of the U.S.-backed Syria Democratic Forces, or SDF, as an extension of the Kurdish insurgency that is raging in southeastern Turkey.

“We will continue until we uproot this terror organization,” Erdogan told the rally.

A spokesman for a Syrian rebel group said the Turkish-backed offensive will continue south of Jarablus to clear IS and Kurdish forces from northeastern Aleppo. Turkish leaders have vowed to drive both IS and the Kurdish People’s Protection Units, or YPG, away from the border.