Syrian government or Russian air strikes targeted US-backed Syrian militias in Deir al-Zor province at dawn on Saturday, a militia official told Reuters.
Ahmed Abu Khawla said the strikes injured six fighters from his group, the Syrian Democratic Forces, an alliance of Kurdish and Arab militias battling Islamic State with the US-led coalition.
The jets came from government territory and hit positions on the eastern bank of the Euphrates river, said Khawla, who heads the Deir al-Zor military council fighting under the SDF.
The US-backed SDF and Syrian government forces, supported by Russian and Iran-allied groups, have been converging on Islamic State in separate offensives in Deir al-Zor.