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.
A notorious Syrian army commander known is set to head a military offensive to capture opposition-held territory in northern Hama.
The Sawaiq al-Rahman Brigade has announced it has killed several Nusra Front fighters, as clashes between opposition groups continue.
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.
A local Islamic court ordered a blockade of the regime-held city of Idlib until the women were released.
After weeks of defeats, Kurdish forces are now on the advance against Islamic State positions following reinforcements by Peshmerga and rebel units.
The Islamic State group have tightened their siege of the town, cutting off a vital air-drop site used for delivery of food and weapons.