The U.S. Coalition clashed with an unknown group in northeastern Aleppo this week after the latter opened fire on a base near the city of Manbij, Al-Masdar News reports.

“They [coalition forces] received gunfire from undisclosed persons and returned fire, and it ended quickly, skirmish at best,” Army Colonel Sean Ryan, Spokesman for Operation Inherent Resolve (OIR), told Kurdistan 24.

“But we don’t know who fired and it was during a US-MMC [Manbij Military Council] patrol,” he added.

According to Kurdistan 24, a Syrian Kurdish journalist Hosheng Hesen posted a video on his Twitter account that reportedly showed the clashes between US troops in Manbij and armed rebel factions backed by Turkey.

“US troops stationed in Manbij clash with the Turkish-backed armed factions. On the 15th of this month, the armed Turkish-backed factions targeted the village of Bughaz in Manbij,” he wrote on Twitter.