A convoy of about 40 Russian troops which was heading for the town of Tall Tamr was stopped by a U.S. patrol, the Syrian Observatory for Human Rights (SOHR) reports.
"This caused a state of tension between both parties," SOHR writes. As a result, the Russians retreated and headed towards the city of Ain Issa.
On January 14, the Syrian Observatory also reported that a U.S. patrol stopped a Russian convoy on the road between the cities of Al-Hasakah and Qamishli.
After Turkey began its military operation in northern Syria, the U.S. troops left a number of military bases in Syria and relocated to the oil fields.
Currently, U.S. troops are stationed at 11 military bases and locations in Syria's Hasakah, Raqqa and Deir Ezzor provinces.