US downs pro-Syrian drone that fired at coalition forces: Spokesman

Washington: The United States shot down a pro-Syrian government drone that fired toward U.S.-led coalition forces in Syria on Thursday, a U.S. 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 U.S. Army Colonel Ryan Dillon, a spokesman for the U.S.-led coalition fighting Islamic State, told reporters the drone meant to attack them and dismissed the possibility it had fired a warning shot.

Dillon said the United States had earlier carried out a strike against pick-up trucks with weapons that had moved against U.S.-backed fighters near the southern town of At Tanf. 

It was the third such strike in as many weeks by the Pentagon, which has sought to stay out of Syria`s civil war to focus firepower instead on Islamic State in Syria and Iraq. 

On Tuesday, the United States launched an air strike against Iranian-backed fighters who it said posed a threat to U.S. and U.S.-backed forces in southern Syria.

A military alliance fighting in support of President Bashar al-Assad threatened on Wednesday to hit U.S. positions in Syria, warning its "self-restraint" over U.S. air strikes would end if Washington crossed "red lines".

In recent days, the U.S. military has repeatedly warned massing forces to stay away from a `deconfliction zone` near a garrison used by American special forces and U.S.-backed fighters around At Tanf.

The zone was agreed with Russia, Syrian President Bashar al Assad`s ally. Assad is also backed by Iran and Shi`ite militias. 

Tanf is part of a region known as the Badia, a vast, sparsely populated desert territory that stretches to the Jordanian and Iraqi borders and was declared a military priority by Syria`s foreign minister in May.