The ferocious and chaotic nature of the conflict in the area was demonstrated by an encounter between American Special Forces and a trained Russian force in eastern Syria that included mercenaries from the Wagner Group. 

In eastern Syria, a fierce battle unfolded between American Special Forces and a trained Russian force consisting of mercenaries from the Wagner Group. The clash took place at a Conoco natural gas refinery and involved intense artillery fire and tank advancements. The American troops, supported by aircraft like F-15E strike fighters and Apache attack helicopters, faced a significant challenge against the Russian guns and armored vehicles. The battle scene was chaotic and marked one of the deadliest encounters for the US military in Syria. Despite being outnumbered and outgunned, the Special Forces soldiers fought back, using heavy machine guns mounted on their armored trucks to engage the advancing enemy. The Russian tanks posed a serious threat, but the American troops managed to hold their ground and repel the attack. The battle highlighted the complex dynamics in Syria’s civil war, with opposing forces including ISIS, Syrian government troops, Russian mercenaries, and American troops often operating in proximity. 

Source: https://thewarhorse.org/special-forces-soldiers-reveal-first-details-of-battle-with-russian-mercenaries-in-syria/