The war in Syria was already complicated. Now a border skirmish is adding a new level of intrigue

Reporting from Amman, Jordan â€”  Syrian rebels backed by Turkish tanks clashed with Kurdish-aligned militiamen near a border city on Saturday, opposition groups and Kurdish factions said, adding yet another complication to the morass of Syria’s civil war.

The battle marked a breakdown of a fragile equilibrium that had been established after Kurds and Turks, backed by the United States, helped Syrian rebels oust Islamic State jihadists from a border city last week.

Kurds have long been at odds with Turkey over their desire for an independent homeland, and Turkey has been battling a stubborn Kurdish insurgency.

In the aftermath of last week’s battle for the border city of Jarabulus, a U.S.-supported Kurdish militia said it would heed Vice President Joe Biden’s warnings and withdraw to areas east of the Euphrates river to avoid confrontations with the Turkish-backed fighters who had wrested control of the area from Islamic State jihadists.

But when a broader Kurdish-dominated alliance called the Syrian Democratic Forces refused to leave the village of Amarneh, roughly five miles south of Jarabulus, Turkey-backed Syrian opposition groups launched an offensive to dislodge the group and consolidate their grip over areas taken from Islamic State.

One Turkish soldier was killed and three were wounded in a rocket attack during the fight, according to Turkey’s official Anadolu news agency.

The battle presented a thorny situation for military planners of the U.S.-led coalition, which has launched sorties and provided reconnaissance and logistical support to both the Kurdish fighters and the Free Syrian Army, the primary belligerents on Saturday.

A child waves toward Turkish troops heading to the Syrian border, in Karkamis, Turkey, Friday, Aug. 26, 2016.

(Halit Onur Sandal / AP )

The U.S. has pinned its hopes on the Kurdish fighters and the Kurdish-led alliance, known as the Syrian Democratic Forces, becoming its main strike force against Islamic State. Yet it also assisted the Turkish-led rebel offensive on Jarabulus, dubbed “Operation Euphrates Shield,� on Wednesday.

That offensive successfully ousted Islamic State jihadists from the city. But the Turks also hoped it would sabotage Kurdish-led plans to integrate the area into an autonomous Kurdish “corridor� extending across a long stretch of the Syrian-Turkish border.

Ankara has insisted it would not accept any such entity along its borders because it would galvanize Kurdish groups in Turkey to pursue their secession plans. In the wake of “Euphrates Shield,� both sides have engaged in what amounts to a land-grab aimed at denying the other control of the border territories even while they continue clashes with Islamic State fighters still bunkered in some areas.

In Saturday’s clash, Turkish tanks stationed nearby in Jarabulus rushed deeper into Syrian territory to provide fire support to the Syrian rebels battling for Amarneh, according to Mustafa Sijri, spokesman of the Free Syrian Army’s Mutassem Brigade. Their incursion came hours after Turkish F-16’s pounded the village.

The Jarabulus Military Council, which is allied with the Syrian Democratic Forces, called the Turkish incursion “a dangerous precedent and escalation.� It said the airstrikes had led to civilian casualties in the village.

Another faction fighting under the Syrian Democratic Forces banner, the Army of the Revolutionaries, demanded the U.S.-led coalition explain the justification for the Turkish assault, and accused Turkey of supporting hardline Islamist groups, including the formerly Al-Qaeda affiliated Front for the Conquest of Syria.

Jarabulus lies in the middle of two Kurdish-dominated swaths of land. The Syrian Democratic Forces had hoped to consolidate the city and its environs into a Kurdish-controlled area.

But the U.S., which had in recent weeks given vital air cover to the Kurdish-led groups in their campaign on the nearby city of Manbij, chastised Kurdish fighters within the Syrian Democratic Forces for setting their sights on Jarabulus.

“No corridor, period. No separate entity on the Turkish border,� said Biden in a press conference on Wednesday, adding that “elements that were part of the Syrian Democratic Forces ... must move back across the [Eurphrates] river.� He specified that the “elements� he was referring to were the People’s Protection Units, a Kurdish group better known by its initials, the YPG.

“They cannot, will not, and under no circumstances get American support if they do not keep that commitment, period,� he said.

A Syrian Kurdish journalist, Welat Bakr, said Kurds were outraged the United States had asked them to leave the area.

“Unofficial numbers say the YPG sustained 800 martyrs in the fight for Manbij, and then America comes and asks them to withdraw? This has shocked the Kurdish street,� he said.

He added that the Kurdish group had been left in an awkward position: If it does as the U.S. requests, it risks losing support among its followers; if it doesn’t, it risks losing U.S. support.

Although it said on Wednesday that it would withdraw its forces, the YPG appeared to follow a literal interpretation of Biden’s edict and left behind its Arab partners in the Syrian Defense Forces to hold the area.

YPG spokesman Redur Xelil said Friday that the group had no members left near Jarabulus and Manbij. However, Sijri, the rebel spokesman, said they were still present.

The battles set the stage for a race to see who will take the city of Al-Bab, located 23 miles northeast of Aleppo city and still held by Islamic State. Like Manbij and Jarabulus, Al-Bab represents another link in the projected Kurdish corridor.

They also further complicate the coalition’s fight against Islamic State. Although the jihadist group has recently lost ground, it has been adept at taking advantage of fighting among the array of belligerents on the Syrian battlefield. On Saturday, it launched a counter-offensive to retake Al-Raii, 34 miles southeast of Jarabulus, from the Turkish-backed groups.

Bulos is a special correspondent.

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