The U.S.-led anti-ISIS coalition on Thursday confirmed it struck forces supporting Syrian President Bashar al-Assad, marking the third such incident near a key border town in southern Syria.

Axar.az reports citing Yeni Safak.

"The #Coalition does not seek to fight Syrian regime or pro-regime forces," coalition spokesman Army Col. Ryan Dillon wrote on Twitter. "However, we remain ready to defend ourselves against any threat.”

The "Pro-regime forces" could include Assad's Syrian Arab Army, Lebanese Hezbollah, Iranian forces, or irregular Syrian forces known as Shabiha.

The strikes targeted two light attack vehicles Dillon said were determined to pose a threat to coalition forces stationed at a garrison in the southeastern border town of at-Tanf.

The coalition has been training partner forces at the base for several months.

Speaking to reporters at the Pentagon from Baghdad, Dillon also confirmed a U.S. aircraft shot down an armed pro-regime drone that targeted coalition forces.

That strike "was clearly meant as an attack on coalition forces and our partner forces in the area," he said.

Two previous coalition strikes hit pro-Assad forces near the garrison May 18 and June 6 after the coalition said they posed a threat to it and partner forces.