Syrian opposition activists said anti-regime protesters have captured at least two army checkpoints in the eastern province of Deir Ezzour
The Britain-based Syrian Observatory for Human Rights said the protests occurred in regime-held areas close to those controlled by US-backed fighters on the east bank of the Euphrates river.
It said the protests began after Friday prayers.
Protesters marched toward and captured two checkpoints.
When they tried to march to the village of Salhiyeh, troops opened fire, killing one person and wounding others.
The Deir Ezzour 24, an activist collective, said three people were killed and more than 10 wounded in the protests. It said protesters demanded Syrian regime troops and Iran-backed militiamen leave the province.
Deir Ezzour borders Iraq is home to Iran-backed militias.