A US coalition spokesman said the concern is that such strikes could take away attention from the fight against IS militants
The United States shot down a pro-Syrian government drone that fired toward US-led coalition forces in Syria on Thursday, a US military spokesman said, in a major escalation of tensions between Washington and troops supporting Damascus.
The armed drone "hit dirt" and there were no injuries or damage done to the coalition patrol in southern Syria. But US Army Colonel Ryan Dillon, a spokesman for the US-led coalition fighting the Islamic State (IS) group, said the drone meant to attack the patrol and dismissed the possibility it had fired a warning shot.
"This clearly showed a threat even if it were a warning shot; it was something that showed a hostile intent, a hostile action and posed a threat to our forces because this drone still had munitions that were still on it," Dillon said.
He added that it was the first known time that pro-Syrian government forces had fired at coalition forces in that region.
A US official, speaking on condition of anonymity, said the munition landed a few hundred yards from coalition forces and it failed to explode.
Dillon said the US had earlier in the day carried out a strike against two pro-Syrian government pick-up trucks with weapons that had moved against US-backed fighters near the southern town of At Tanf.
It was the third such strike in as many weeks, and the second this week, by the Pentagon, which has sought to stay out of Syria's civil war to focus firepower instead on IS in Syria and Iraq.
"Unfortunately, there have been [these] incidents that have taken our focus away from fighting ISIS," Dillon said, using another acronym for IS.
The Syrian Democratic Forces (SDF) launched their assault to capture Raqqa, Islamic State's de facto Syrian capital.
For months, air strikes and special forces from the US-led coalition have helped them encircle the city, which IS seized in 2014 and has used as a base to plan attacks abroad.
On Tuesday, the United States launched an air strike against Iranian-backed fighters who it said posed a threat to US and US-backed forces in southern Syria.
A military alliance fighting in support of President Bashar al-Assad threatened on Wednesday to hit US positions in Syria, warning its "self-restraint" over US air strikes would end if Washington crossed "red lines".
In recent days, the US military has repeatedly warned massing forces to stay away from a "deconfliction zone" near a garrison used by American special forces and US-backed fighters around At Tanf.
The zone was agreed with Russia, Assad's ally.