Maghaweir al-Thowra thwarted an attack by the regime army and allied militias in a desert area east of Homs province, leaving a dozen and wounded, the rebel group said Wednesday.
The US-backed Maghaweir al-Thowra group said the attack took place in a de-escalation zone near the Iraqi border.
Bashar al-Assad, who now controls around 60 percent of the country, has vowed to reclaim the rest.
Maghaweir al-Thowra has been playing key role in the delivery of aid to the al-Rukban camp on the Jordanian border and to the displaced people near the al-Tanf border crossing with Iraq.
Eight years of war in Syria has killed 560,000 people and driven half the pre-war population of 22 million from their homes, including more than 6 million as refugees to neighbouring countries.
This article was edited by The Syrian Observer. The Syrian Observer has not verified the content of this story. Responsibility for the information and views set out in this article lies entirely with the author.