A drone attack hit a compound run by US troops and US-backed Syrian opposition fighters in possible revenge by Iran-backed militia over Israel-attributed strikes a day earlier.

The United States military said in a statement that the Monday attacks in eastern Syria had no casualties, adding, "Operation Inherent Resolve forces, in coordination with our Maghaweir al-Thowra partners, responded to an attack by multiple unmanned aerial systems in the vicinity of Al-Tanf Garrison," located near where the borders of Syria, Jordan and Iraq meet.

Maghaweir al-Thowra are US-backed Syrian opposition fighters, trained by US and coalition troops at Al-Tanf to counter Islamic State (ISIS) militants.

On Tuesday, rockets were also fired at the Green Village at the US-controlled Al-Omar oil field in eastern Syria. The oil field in Deir ez-Zur province is Syria’s largest and US personnel and the YPG/PKK militants are present there. “The attack injured two US service members, one was treated and released, while the other is under evaluation for traumatic brain injury,” The Special Operations Joint Task Force-Levant said.

There was no claim of responsibility for either of the attacks but a Syrian opposition source told Israel’s Kan public broadcaster that Iran is believed to have carried out the attacks, and the Wall Street Journal said, “The shelling follows a long-running series of attacks on US forces and local partners in Iraq and Syria carried out by Iran and its allied paramilitary groups in the region.”

On Sunday, a series of Israeli airstrikes hit Iranian targets close to Russia's main Syrian bases on the Mediterranean coast and areas near the ancestral home region of the Syrian president. Three servicemen were killed and three were wounded in two simultaneous attacks south of the province of Tartous, and another on the northeastern outskirts of capital Damascus.