A spokesperson for the US-led coalition force fighting the so-called "Islamic State" (IS) stated on Friday that a US F-15 fighter jet had shot down a drone on Thursday after the unmanned device dropped munitions near al-Tanf (above), a border post along the border of Iraq where US-backed rebels are preparing for operations against IS.
US Army Colonel Ryan Dillon said the drone was intended to attack the US-backed forces in the area.
"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 had munitions that were still on it," Dillon said.
Dillon reported the drone "hit dirt" and caused no injuries to coalition forces.
CNN and Reuters cited an anonymous official who said that the drone appeared Iranian-made. Iran, along with Russia, is allied with Syrian President Bashar al-Assad.
An unusual move for the US
The drone was shot down the same day that coalition forces also destroyed two pro-regime vehicles that had been moving towards al-Tanf.
The US previsouly conducted airstrikes in May on Syrian forces that had violated a so-called "deconfliction zone" boundary. However, Dillon noted that the drone drop marked the first time that pro-Syrian regime forces had been known to attack US-backed rebels in the area.
The military action marks an unusual operational departure for US forces. Up until now, they have focused their efforts against IS militants in both Syria and Iraq and sought to avoid engagement with pro-regime forces, which includes Iranians, Shiite militia and Lebanese militant group Hezbollah, which is backed by Iran.
However, a statement from the US Central Command made it clear that they would not rule out further action against perceived threats from pro-regime forces, stating: "The coalition will take appropriate measures to protect our forces."
Dillon reiterated the Command's statement in a tweet.
The al-Tanf "deconfliction zone" lies in a sparsely populated desert area near the border with Iraq and Jordan.
The area is highly contested, raising the possibility of mistakes or miscalculation that could quickly escalate between multiple armed actors on the ground.
The Assad regime has not controlled Syria's border with Iraq for three years, and is pushing to take control of the border before US- backed forces from the north and south converge. On the opposite side of the border in Iraq, Iran-backed Shiite militia known as Popular Moblization Units have pushed back IS and secured large sections of the border. Shiite militia leaders in Iraq have suggested they may next move into Syria.
For Iran and Hezbollah, controlling the border would create a land corridor running from Tehran to Beirut, something the United States is seeking to block.
In a new development, Russia's defense ministry on Friday said pro-regime forces had circled around US-backed rebels near al-Tanf to reach the Iraqi border. If true, the move effectively blocks US-backed rebels from advancing north.
Sergei Surovikin, the commander of Russian forces in Syria, said the pro-regime forces were advancing towards Boukamal, a Euphrates River valley town on the Syrian side of the Iraqi border.
Raqqa fighting causes UN concern
Meanwhile, fighting intensified in Raqqa as the US-backed Syrian Democratic Forces (SDF) continued battling IS militants in the terror group's last major stronghold in Syria. The US has been supporting the SDF with airstrikes.
The recent airstrikes led the United Nations to express again its concern over the status of civilians in the besieged city.
"Airstrikes and shelling in Syria's Ar-Raqqa city have placed thousands of civilians at risk and intensified an already desperate humanitarian situation," a statement from the UN Office for the Coordination of Humanitarian Affairs said.
The statement also noted that while some 95,000 have already fled the city, an estimated 50,000-100,000 people remain in the city.
UNICEF, the UN's children agency, also issued a statement expressing concern over the plight of children in Raqqa, claiming that over 25 children have been killed in the fighting.
UNICEF also expressed concern for the estimated 80,000 children who have become internally displaced as a result of the fighting in Raqqa.
cw/cmb/jm (dpa. Reuters, AP)