The gunman involved has been killed, with no information on motives as of yet.

Syrian security forces and United States soldiers have come under fire during a joint field patrol near Palmyra, in the central Homs region, leaving two Syrian personnel and several US service members wounded, the official Syrian Arab News Agency (SANA) state news agency reported.

The assailant was killed in the incident on Saturday, with no further details regarding the motive or circumstances, SANA reported.

Traffic on the Deir Ezzor–Damascus highway was temporarily halted as military aircraft conducted overflights in the area, the agency said.

A security source told SANA that US helicopters evacuated those who were wounded to the al-Tanf base near the Iraqi border.

There was no immediate comment from the Pentagon.

The US has troops stationed in northeastern Syria as part of a decade-long effort to help a Kurdish-led force there combat ISIL (ISIS).

ISIL captured Palmyra in 2015, at the height of their military ascendancy in Syria, before losing the city 10 months later. During that time, it destroyed several ancient sites and artefacts while using others to stage mass executions.

ISIL was vanquished in Syria in 2018, but still carries out sporadic attacks without controlling any territory inside Syria.

The war-ravaged nation has just marked one year since the ouster of longtime leader Bashar al-Assad, but continues to face stiff security and economic challenges as it seeks to rebuild and recover after 14 years of ruinous civil war.