The Kurdish militia known as the People's Protection Units (YPG) and rebel opposition forces are reportedly fighting each other in the small Syrian town of Marea, north of Aleppo.
Both groups are backed by the United States.
"President Barack Obama's confused strategy in Syria means towns are now being fought over by different US-backed groups," reports The Telegraph.
The YPG is the armed wing of the of the Kurdish Democratic Union Party (PYD) that controls large swathes of northern Syria and is considered a terrorist group by Turkey, a U.S. NATO ally.
"It is not new to say that the war in Syria has become a complex mess, spiraling out of control. Analysts -- and many American diplomats who have left the administration, some in disgust -- say that the mess is a consequence of President Obama's decision to support the rebellion against President Bashar al-Assad, but only half-heartedly," reports The Telegraph.
"He sent in weapons to support the rebels -- including in Marea. But he also refused to confront Russia and the regime, who had far more weapons, leaving the rebels lightly armed sitting ducks," it adds. "Then he also decided to support the Kurds."
The Telegraph goes on to note that the Obama administration wanted the Syrian Kurds to fight the Islamic State (ISIL/ISIS), but they also took on anyone who prevented the establisment of a Kurdish state in northern Syria.
"That now means rebel areas like Marea, north of Aleppo, which is between that mini-state's western and eastern halves," adds the report. "As a result, the town is being fought over by two western proxies."
A "cessation of hostilities" negotiated in Munich, Germany, between the United States, Russia, and other parties was supposed to begin on Friday, but the fighting continued in Marea and everywhere else in Syria.
Rebels in Marea are now fighting ISIS, the Bashar al-Assad regime, Russian bombers, and the YPG, points out The Telegraph.
The YPG has been linked to to the leftist Kurdistan Workers Party (PKK), which has been designated a terrorist group by the United States and some of its Western allies.
"Despite that designation, the YPG's strength comes in part from its backing from the United States, which gave it air support in its bitter and eventually successful defence against [ISIL] of the border town of Kobane," reports the The Telegraph.
"But as the YPG attacks rebel-held areas north of Aleppo it is also fighting the very rebel groups who two years ago drove [ISIL] out of western Syria, and who still face off against it just two miles east of Marea," it adds.
Last week, rebel forces in Marea were reportedly forced to fight ISIS and the YPG at the same time.
"If Marea falls -- to either the YPG or [ISIL] -- it would be a disaster for its embattled inhabitants, but also for the US," explains The Telegraph. "For they were at the heart of attempts by the western and Gulf opponents of the Assad regime to build a united opposition."
Turkey, a U.S. NATO ally, opposes a Kurdish mini-state in northern Syria, along its border. It considers the YPG and the PKK terrorist groups.
"It is quite extraordinary that Obama administration policy seems to be favoring a Kurdish militia group that is incontrovertibly linked to the terrorism-designated PKK over and above a fellow Nato ally, Turkey," reportedly said Charles Lister, an analyst who has been involved in European-sponsored negotiations with a wide array of rebel forces.