Rebels launched a surprise attack on several IS checkpoints and positions around midday on Saturday near the town of Tadmur, sources tell al-Araby al-Jadeed.
Analysis: The US-led aerial campaign may be forcing the Islamic State group to retreat in certain areas, but troops loyal to Damascus - not opposition militias - are making up the ground.
Analysis: A wave of Syrian regime troops are making headway in opposition-held territories in Latakia. Rebels say they will resort to unconventional warfare to break the siege.
Continued bloodshed made 2014 a disastrous year for revolutionaries, not just with the loss of the symbolic city of Homs to the regime, but also the rise of a new foe, the IS group.
Hama activists says release of 60 mainly women and children prisoners came after rebel fighters threatened to cut off water and power to pro-regime areas.